This was CNBC's live blog tracking developments on the war in Ukraine on Tuesday. See here for the latest updates. 

Luxembourg's foreign minister says he does not believe Turkey will block Sweden's and Finland's NATO membership bids despite the Turkish president's objections.

Russia has played down the possible impact of Finland and Sweden joining NATO while Turkey continues to object to their bids to join the Western military alliance.

Both countries plan to send delegations to Turkey in an effort to convince the country, itself an important NATO member, to accept their bids. Moscow has warned of "retaliatory steps" if the countries join the alliance, with Russian President Vladimir Putin describing the development as "a problem."

Meanwhile, Ukraine says the Russian army has lost 27,900 soldiers since its invasion of Ukraine on Feb. 24, according to NBC News.

More than 260 Ukrainian fighters, including some who are badly wounded, were evacuated Monday from a steel plant in the ruined city of Mariupol and taken to areas under Russia's control, the Ukrainian military said.

The fate of the city hangs in the balance now, with Russia poised to take full control, although further evacuations are expected to take place from the steelworks.

Ukraine says Russia's army has lost 27,900 soldiers since the war started

The Russian army has lost 27,900 soldiers since its invasion of Ukraine on Feb. 24, the Ukrainian Defense Ministry said in a video on Telegram, NBC News reported.

In March, NATO estimated between 7,000 and 15,000 Russian troops had died within the first month of the war, according to NBC News.

Last week, Ukraine announced that 501 members of its National Guard had died since the invasion started, NBC News reported. The National Guard serves as a military unit with law enforcement powers and was formed in 2014 when Russia annexed the Black Sea peninsula of Crimea.

— Chelsea Ong

Turkey will not block Sweden and Finland NATO membership requests: Luxembourg foreign minister

Luxembourg's foreign minister says he does not believe Turkey will block Sweden's and Finland's NATO membership bids despite the Turkish president's objections, the Associated Press reported.

Sweden and Finland are submitting their membership applications to the alliance as Russia's invasion of Ukraine continues. But all 30 NATO member countries, among them Turkey, must agree to let these countries join.  

However, Turkish President Recep Tayyip Erdogan has said he opposes the two countries joining NATO, referencing the hosting of members of the Kurdistan Workers' Party, which Turkey classifies as a terrorist group.

Nonetheless, Luxembourg's foreign minister, Jean Asselborn, told Germany's Deutschlandfunk radio he suspects Erdogan is "pushing up the price" for the countries to join the alliance, the Associated Press reported.

"At the end of the day, I am convinced that Turkey can't slam the brakes on this," Asselborn said, according to the Associated Press.

— Chelsea Ong

U.S. Senate advances nearly $40 billion Ukraine aid bill

The U.S. Senate advanced a nearly $40 billion aid package for Ukraine.

The chamber voted to move ahead with the bill by an 88-11 margin. All of the senators who opposed the measure were Republicans.

A final vote on the military and humanitarian assistance could take place as soon as Thursday. Once the Senate passes the bill, it will head to President Joe Biden's desk for his signature.

Senate leaders wanted to approve the bill quickly last week, but Sen. Rand Paul, R-Ky., blocked the unanimous consent needed to pass it.

— Jacob Pramuk

WHO wants investigation into Russian attack on Ukrainian health facilities

The World Health Organization called for investigations into Russian attacks on health-care facilities and ambulances in Ukraine.

The global health agency has documented 226 attacks since Russia invaded its neighbor on Feb. 24, according to Dr. Hans Kluge, WHO regional director for Europe. At least 75 people died and 49 were injured in the attacks, he said.

"These attacks are not justified and they are never OK. And they must be investigated," Kluge said during a press briefing at the Ukraine Media Center in Kyiv.

The WHO will contribute to any investigation that takes place in the future, Kluge added.

— Annika Kim Constantino

Cannes Film Festival opens with Zelenskyy video address

After a canceled 2020 edition and a scaled back gathering last year, the Cannes Film Festival kicked off with an eye turned to Russia's war in Ukraine and a video message from Ukrainian President Volodymyr Zelenskyy.

Formally attired stars including Eva Longoria, Julianne Moore, Bérénice Bejo and "No Time to Die" star Lashana Lynch were among those who streamed down Cannes' famous red carpet for the opening of the 75th Cannes Film Festival and the premiere of Michel Hazanavicius' zombie comedy "Final Cut."

More star-studded premieres — "Top Gun: Maverick!" "Elvis!" — await over the next 12 days, during which 21 films will vie for the festival's prestigious top award, the Palme d'Or. But the opening and the carefully choreographed red-carpet parade leading up the steps to the Grand Théâtre Lumiére again restored one of the movies' grandest pageants after two years of pandemic that have challenged the exalted stature Cannes annually showers on cinema.

But the war in Ukraine remained in Cannes' spotlight. During the festival's opening ceremony, Zelenskyy spoke at length about the connection between cinema and reality, referencing films like Francis Ford Coppola's "Apocalypse Now" and Charlie Chaplin's "The Great Dictator" as inspirations to him.

"The power they've taken from the people will be returned to the people," said Zelenskyy.

— Associated Press

State Department launches new program to track Russian war crimes in Ukraine

The U.S. State Department announced the launch of a new program dedicated to documenting "Russia-perpetrated war crimes and other atrocities in Ukraine."

The program, dubbed Conflict Observatory, will analyze and preserve publicly and commercially available data, including satellite imagery and information shared via social media platforms.

The State Department said that the program received an initial $6 million investment and is expected to secure future funding from the European Democratic Resilience Initiative.

Reports and analyses generated from the program will be available online through the ConflictObservatory.org website.

— Amanda Macias

Macron and Zelenskyy speak about additional weapons deliveries and Ukraine's application to join the EU

French President Emmanuel Macron spoke with Ukrainian President Volodymyr Zelenskyy, according to a readout of the call from the French president's office.

Macron asked for an update on the ground, including the evacuations from Mariupol and from the Azovstal steel plant. He also asked about the need for additional arms for Ukrainian troops.

The French president confirmed to Zelenskyy that arms deliveries will continue and even ramp up in the coming days and weeks, as will the delivery of humanitarian aid.

The two presidents also discussed Ukraine's application for membership in the European Union.

— Amanda Macias

Amnesty International raises concerns following reports Ukrainian troops surrendered at Azovstal plant

Amnesty International raised concerns following reports that Ukrainian forces holed up in Mariupol's Azovstal steel plant surrendered to Russia's armed forces.

"Amnesty International has documented summary killings of captives by Russia-backed separatist forces in eastern Ukraine, as well as the extrajudicial executions of Ukrainian civilians by Russian forces in recent weeks. The Azov Battalion soldiers who surrendered today must not meet the same fate," wrote Denis Krivosheev, Amnesty International's deputy director for Eastern Europe and Central Asia.

Krivosheev added that prisoners of war should have immediate access to medical treatment and should not be subjected to "any form of torture or ill-treatment."

"The relevant authorities must fully respect the rights of prisoners of war in accordance with the Geneva conventions," he said, referencing international humanitarian law.

— Amanda Macias

Ukraine foreign minister discussed arms supply and new sanctions with Dutch counterpart

Ukrainian Foreign Minister Dmytro Kuleba discussed arms supplies and the application of new sanctions against Russia during a meeting with his Dutch counterpart Wopke Hoekstra.

"Commended him and the Dutch government for their efforts to defend peace in Ukraine and Europe. We focused on further arms supplies, new sanctions on Russia, and Ukraine's EU candidate status," Kuleba wrote on Twitter.

— Amanda Macias

Yellen says EU could combine tariffs on Russian oil with embargo

The European Union could combine import tariffs on Russian oil with the phased oil embargo it is trying to put in place to shrink Russia's energy revenues, U.S. Treasury Secretary Janet Yellen said.

The tariff concept will be presented at a G7 finance leaders meeting this week as an economically less costly way to siphon away oil revenues from Moscow while producing faster results, U.S. Treasury officials told reporters.

The tariff plan would aim to keep more Russian oil in the global market, limiting price spikes spurred by a full embargo, while limiting the amount of money Russia can earn from exports, the officials said.

The European Commission, the EU's executive body, has proposed an embargo on imports of Russian crude that would start to phase in next year in response to Moscow's war in Ukraine, but some eastern European countries heavily dependent on Russian oil object to the plan.

Yellen said she discussed a wide range of options for reducing European dependence on Russian energy with European Commission President Ursula von der Leyen in Brussels and added that tariffs and embargoes "are two things that could be combined."

— Reuters

Blinken speaks to wife of WNBA star Brittney Griner

Secretary of State Antony Blinken spoke with the wife of detained WNBA star Brittney Griner on Saturday, a senior State Department official confirmed to NBC News.

In February, the Olympian was arrested on drug charges after a search of her luggage at the Sheremetyevo International Airport near Moscow allegedly turned up vape cartridges with cannabis oil, Russian authorities said.

The offense could carry a maximum sentence of 10 years in prison.

Blinken told Cherelle Griner that her wife's case has his full attention and that the State Department is working on it day and night, according to the official. Blinken also told Griner's wife that the two should stay in touch over the course of Griner's detention.

Last week, Griner's pre-trial detention was extended for a month.

— Amanda Macias

White House confident NATO can reach deal on Swedish, Finnish membership

The Biden administration is confident NATO can reach consensus about bids by Sweden and Finland to join the organization, White house press secretary Karine Jean-Pierre said, amid pushback from NATO member Turkey.

The remarks, made to reporters aboard Air Force One, echoed similar statements by Secretary of State Antony Blinken.

Turkey's objections appeared to have come as a surprise also in Washington, whose relations with Ankara have been strained in recent years. The U.S. suspended Turkey from its F-35 fighter jet program over Turkey's decision to purchase a Russian missile defense system.

Turkish Foreign Minister Mevlut Cavusoglu was traveling to Washington for meetings Wednesday with Blinken.

— Reuters and Associated Press

UN says 3,752 killed in Ukraine since start of war

The United Nations has confirmed 3,752 civilian deaths and 4,062 injuries in Ukraine since Russia invaded its ex-Soviet neighbor on Feb. 24.

The Office of the U.N. High Commissioner for Human Rights said the death toll in Ukraine is likely higher, because the armed conflict can delay reports.

The international body said most of the civilian casualties recorded were caused by the use of explosive weapons with a wide impact area, including shelling from heavy artillery and multiple launch rocket systems, as well as missiles and airstrikes.

— Amanda Macias

International Criminal Court sends its largest forensics team ever to Ukraine

The International Criminal Court deployed a team of 42 investigators, forensic experts and support personnel to Ukraine as the analyzes potential war crimes.

"This represents the largest ever single field deployment by my office since its establishment," Karim Khan, the chief prosecutor for the world's highest court, said in a statement.

Khan added that the team will collect more testimonial accounts, identify relevant forensic materials and "ensure that evidence is collected in a manner that strengthens its admissibility in future proceedings before the ICC."

Russian officials have previously denied any knowledge of war crimes committed in Ukraine.

— Amanda Macias

Biden will meet with leaders of Finland and Sweden at the White House this week

President Joe Biden will welcome Prime Minister Magdalena Andersson of Sweden and President Sauli Niinistö of Finland to the White House this week. 

"The leaders will discuss Finland's and Sweden's NATO applications and European security, as well as strengthening our close partnerships across a range of global issues and support for Ukraine," the White House said in a statement.

Kremlin officials have slammed Finland and Sweden's recent bids to join NATO saying any future expansion of the military alliance will be viewed as a "grave mistake" with global consequences.

— Amanda Macias

Finland's Parliament approves NATO application

The proposal to apply for membership of the NATO military alliance has been overwhelmingly backed in the Finnish Parliament.

Lawmakers voted 188 to 8 in favor of the application in a vote on Tuesday afternoon.

—Matt Clinch

Putin warns Europe on energy price rises

Vladimir Putin has sought to ward off Europe from imposing strict sanctions on Russian oil, by saying that it would cause economic activity in the region to subside.

In comments translated by Reuters, he said that EU countries would not be able to completely ditch Russian oil and the region would end up with the most expensive energy resources.

He claimed that Russian oil and gas revenues were still on the rise, and that the possible embargo from Brussels had been behind the recent price surges.

—Matt Clinch

Ukraine's allies must increase funding for the country, Yellen says

U.S. Treasury Secretary Janet Yellen called for Ukraine's allies to step up financial support for the country on Tuesday, saying that funds that have been announced so far would not be sufficient for the country's short-term needs as Russia's invasion continues, Reuters reported.

"Ukraine's financing needs are significant," Yellen said in remarks prepared for delivery to the Brussels Economic Forum, adding that Ukraine's government continued to function due to the courage and resourcefulness of its officials.

"In the months until tax collection can resume at pace, Ukraine needs budget funding to pay soldiers, employees and pensioners, as well as to operate an economy that meets its citizens' basic needs," Yellen said.

"In short order, it will need to turn to repairing and restoring critical utilities and services." 

While Ukraine would eventually need "massive support" for reconstruction and recovery on the scale of the post-World War Two Marshall Plan for Europe, the country would have to take this "one step at a time."

— Reuters

Russia plays down Finland, Sweden NATO bids

Russia's Foreign Minister Sergey Lavrov has played down Finland and Sweden's bids to join NATO, saying it makes "no big difference" if they join as they've long-participated in military drills anyway.

The comments come after military analysts said Russia had little room to retaliate against the move, given that it wants to avoid a direct confrontation with NATO, and the fact that its forces are fully tied-up in Ukraine.

On Monday, Putin initially said the expansion of NATO "is a problem," but later stated that there was no threat to Russia if Sweden and Finland joined. However, Moscow has warned that will respond to any military build-up in the Nordic countries if they are admitted to the alliance.

Status of Mariupol uncertain after evacuation of soldiers from steel plant

There are several unknowns when it comes to the status of the southern port city of Mariupol after hundreds more Ukrainian soldiers were evacuated from the city's Azovstal steelworks complex.

The steelworks was the last stronghold of Ukrainian fighters trying to resist Russian occupying forces in the southern port city.

It's uncertain whether the evacuation has been completed and if not, how many Ukrainian soldiers could still be in the plant. It's also uncertain whether the evacuation means that Ukraine has conceded full control of the city to Russian forces.

Control of the city was a key strategic goal for Russia, which is widely seen as wanting to create a land bridge from Russia to Crimea, via Mariupol.

Remarking on the evacuation of Ukrainian soldiers in the plant, Ukraine's President Volodymyr Zelenskyy said last night that "Ukraine needs Ukrainian heroes alive. This is our principle. I think that every normal person will understand these words."

— Holly Ellyatt

Fighting intensifies in Donbas, with civilian infrastructure under fire, officials say

Fighting between Russian and Ukrainian forces is intensifying in the Donetsk area of the eastern Donbas region, Ukraine's armed forces and officials have said.

Russian enemy aircraft have destroyed civilian and military infrastructure in the region, the armed forces said in an update on Telegram Tuesday morning, while the head of Luhansk's regional administration Serhiy Hayday said on social media this morning that the shelling of settlements in the Severodonetsk area of the Donbas had intensified, with a hospital and residential buildings hit.

He said there were at least ten dead and three wounded during the strikes and posted images of shell-damaged buildings on his Facebook page.

In his nightly address on Monday, Ukraine's President Volodymyr Zelenskyy said Ukraine's armed forces are "holding back constant attacks in those areas where Russia is still trying to advance," with Severodonetsk and other cities in the Donbas region being principal targets for Russia.

— Holly Ellyatt

Putin is taking active role in war decision-making, reports suggest

Russia's President Vladimir Putin is now directly involved in the daily running of the war in Ukraine, according to Western military sources reported in the British media on Tuesday.

The BBC and other British news agencies have said Putin, together with his chief of staff, are "taking decisions normally made by more junior officers," citing unnamed military sources.

One of the sources told the BBC this was further evidence that Moscow's campaign is not going according to plan, and Putin is becoming increasingly frustrated by its setbacks

The Guardian newspaper reported Tuesday that Putin has become involved to the extent that he is making operational and tactical decisions "at the level of a colonel or brigadier."

— Holly Ellyatt

Turkey says it won't approve Finland, Sweden NATO bids

Turkey's President Recep Tayyip Erdogan has reiterated Ankara's objections to Sweden and Finland joining NATO, saying Turkey will not approve the bids.

He claims the countries have harbored people linked to groups Turkey deems to be terrorist organizations.

Finland and Sweden have said they will send delegations to Ankara to try to convince Turkey to accept their bids; Erdogan, however, has said they "should not bother."

"Neither of these countries have a clear, open attitude toward terrorist organizations," Erdogan said at a news conference Monday. "How can we trust them?"

Enlargement of NATO requires the unanimous agreement of the 30 current members.

Turkey accuses Finland and Sweden of harboring members of the PKK, the Kurdistan Workers' Party. The PKK has clashed with Turkish security forces for years but says its aims are greater cultural and political rights for Kurds and the eventual establishment an independent Kurdish state.

CNBC has reached out to the Swedish and Finnish foreign ministries for comment.

Erdogan also said Turkey could not accept the Finnish and Swedish bids because of an arms embargo the countries imposed on Turkey after its incursion into Syria in 2019.

"First of all, we cannot say 'yes' to those who impose sanctions on Turkey, on joining NATO which is a security organization," Erdogan said.

— Holly Ellyatt

Ukraine war could cause 'catastrophic' levels of malnutrition in children, UNICEF warns

The war in Ukraine, along with other global shocks to food security, is creating conditions for a significant increase in life-threatening malnutrition for children, according to UNICEF.

The United Nations agency said in a statement that soaring food prices caused by the war is set to drive up the cost of "life-saving" therapeutic food treatment. It added that severe malnutrition in children could go to "catastrophic levels."

Around 13.6 million children under five suffer from severe wasting — a condition where children are too thin for their height, leading to weak immune systems, the UN agency said in a press release.

The most effective treatment is a ready-to-use therapeutic food, but the price of that is expected to increase by up to 16% in the next six months due to a sharp rise in the cost of ingredients.

"For millions of children every year, these sachets of therapeutic paste are the difference between life and death," said UNICEF Executive Director Catherine Russell.

Around 10 million severely wasted children do not have access to the treatment, and another 600,000 children may lose access at current spending levels, Unicef added.

Before the war in Ukraine began, conflict, climate change and Covid were already making it difficult for families to feed their children, said Russell.

"The world is rapidly becoming a virtual tinderbox of preventable child deaths and child suffering," she said.

"There is precious little time to reignite a global effort to prevent, detect and treat malnutrition before a bad situation gets much, much worse," she added.

— Abigail Ng

Russia likely to use artillery strikes heavily in its advance on eastern Donbas region, UK’s Defence Ministry says

Russia will likely continue relying heavily on massed artillery strikes as it tries to regain momentum in its advance on the eastern Donbas region, said the U.K.'s Defence Ministry in its daily intelligence update.

The update added that Russia had proven it was willing to use strikes against inhabited areas.

Around 3,500 buildings were estimated to have been destroyed or damaged in the Chernihiv region north of Kyiv, during Russia's abandoned advance towards the Ukrainian capital, the ministry said in its update, posted on Twitter. As much as 80% of the damage was caused to residential buildings.

"The scale of this damage indicates Russia's preparedness to use artillery against inhabited areas, with minimal regard to discrimination or proportionality," the ministry said in its update, posted on Twitter.

Russia has possibly relied more heavily on such "indiscriminate" shelling because of its "unwillingness to risk flying combat aircraft routinely beyond its own frontlines," the ministry said.

— Weizhen Tan

More than 260 fighters evacuated from Mariupol steelworks

More than 260 Ukrainian fighters, including some who are badly wounded, were evacuated Monday from a steel plant in the ruined city of Mariupol and taken to areas under Russia's control, the Ukrainian military said.

Deputy Defense Minister Hanna Maliar said 53 seriously wounded fighters were taken to a hospital in Novoazovsk, east of Mariupol. An additional 211 fighters were evacuated to Olenivka through a humanitarian corridor. An exchange would be worked out for their return home, she said.

Malyar said missions are underway to rescue the remaining fighters inside the plant, the last stronghold of resistance in the devastated southern port city.

"Thanks to the defenders of Mariupol, Ukraine gained critically important time to form reserves and regroup forces and receive help from partners," she said. "And they fulfilled all their tasks. But it is impossible to unblock Azovstal by military means."

Ukrainian President Volodymyr Zelenskyy said the evacuation of the fighters from Azovstal to separatist-controlled territory was to save their lives. He said the "heavily wounded" were getting medical help.

"Ukraine needs Ukrainian heroes to be alive. It's our principle," he said. "The work continues to bring the guys home, and it requires delicacy and time."

—Associated Press

President Putin says NATO expansion 'is a problem'

Moscow has wasted no time in making its feelings known about the likely expansion of the Western military alliance NATO, with President Putin saying Monday that it "is a problem."

Putin claimed that the move was in the interests of the U.S., in comments reported by Reuters, and said Russia would react to the expansion of military infrastructure to Sweden and Finland, although he insisted Moscow had "no problems" with the countries.

Putin's comments come after other top Kremlin officials deplored the future expansion of NATO, with one describing it is a "grave mistake" with global consequences.

— Holly Ellyatt

McDonald’s says it will sell its Russia business

McDonald's said Monday that it will sell its business in Russia, a little more than two months after it paused operations in the country due to its invasion of Ukraine.

"The humanitarian crisis caused by the war in Ukraine, and the precipitating unpredictable operating environment, have led McDonald's to conclude that continued ownership of the business in Russia is no longer tenable, nor is it consistent with McDonald's values," the company said in a news release.

Russian forces, directed by President Vladimir Putin, have been accused of an array of war crimes during their assault on Ukraine.

McDonald's exit from Russia is a bitter end to an era that once promised hope. The company, among the most recognizable symbols of American capitalism, opened its first restaurant in Russia more than 32 years ago as the communist Soviet regime was falling apart.

— Mike Calia

Read CNBC's previous live coverage here:

Ukraine says more than 260 soldiers evacuated from Mariupol; Sweden and Finland move to join NATO