• The Pentagon said initial intelligence indicates that Wagner mercenary boss Yevgeny Prigozhin died in a Wednesday plane crash.
• Putin described Prigozhin as a "talented businessman" with a "complicated fate" who "made serious mistakes in his life."
• Prigozhin, who was once Putin's personal chef and confidant, was living in exile following an attempt in June to revolt over frustrations stemming from a lack of Russian battlefield successes in Ukraine.
• CNBC and NBC News have not confirmed Prigozhin's death.

Russian President Vladimir Putin broke his silence Thursday in quick, impersonal remarks to the families involved in the fatal plane crash believed to have killed Wagner mercenary boss Yevgeny Prigozhin.

Prigozhin, who was once Putin's personal chef and confidant, was living in exile following an attempt in June to revolt over frustrations stemming from a lack of Russian battlefield successes in Ukraine.

"With regard to this plane crash, first of all, I want to express my sincere condolences to the families of all the victims. It's always a tragedy," Putin said in a televised speech.

"I've known Prigozhin for a long time, since the early '90′s," Putin said, describing him as a "talented businessman" with a "complicated fate" who "made serious mistakes in his life."

The Russian leader stopped short of confirming Prigozhin's death but did speak in the past tense when referring to the 62-year-old. Putin said an investigation into what happened to the private jet carrying 10 people and departing from Moscow to St. Petersburg was already underway.

The Pentagon said Thursday that initial intelligence indicates that the Wagner chief died in the Wednesday plane crash.

"It's likely Prigozhin was killed and we're continuing to assess the situation," said U.S. Air Force Brigadier General Pat Ryder during a Pentagon briefing.

"The press reporting stating that there was some type of surface-to-air missile; we assess that information to be inaccurate," Ryder said, declining to elaborate further.

CNBC and NBC News have not confirmed Prigozhin's death.

Former deputy national security advisor Ben Rhodes told MSNBC that the attack "was not a mysterious accident."

"This has all the hallmarks of appearing like a military-style takedown," Rhodes said, adding that Prigozhin's fate was eminent following a short-lived mutiny about two months ago.

Former U.S. Navy Admiral James Stavridis, who led the NATO alliance's forces between 2009 and 2013, said Prigozhin's death was a dog whistle to those who dissent from Putin's absolute rule.

"He [Putin] needed to demonstrate who really is running the joint," Stavridis said, describing the attack as a "public execution."

"No real surprise here, it's a marker of how lethal, and how deadly and how unscrupulous Vladimir Putin is," Stavridis added.

Ukrainian President Volodymyr Zelenskyy denied claims that Kyiv was behind the downing of the private jet on Russian soil.

"We have nothing to do with it. Everyone understands who is involved," Zelenskyy said.