• Former President Donald Trump blasted Senate Minority Leader Mitch McConnell, R-Ky., in a lengthy statement released Tuesday.
• Trump vowed to back primary opponents who support Trump's agenda.
• Trump's attack, which describes McConnell as a "dour, sullen, and unsmiling political hack," comes as the Senate GOP leader has publicly accused Trump of bearing responsibility for the deadly Capitol riot.

Former President Donald Trump on Tuesday blasted Senate Minority Leader Mitch McConnell, R-Ky., and vowed to back primary opponents who support Trump's agenda.

The fiery statement, which describes McConnell as a "dour, sullen, and unsmiling political hack," comes after the Senate GOP leader accused Trump of bearing responsibility for the deadly Capitol riot.

Trump, whose once-prolific online presence has been muzzled by multiple social media companies, claimed in a statement from his political action committee that McConnell's "dedication to business as usual" will lead to further Republican losses.

"He will never do what needs to be done, or what is right for our Country," Trump said of McConnell. "Where necessary and appropriate, I will back primary rivals who espouse Making America Great Again and our policy of America First."

The statement, which came three days after Trump was acquitted in an unprecedented second impeachment trial, highlights a widening rift in the GOP over what role the former president ought to play in the party. Trump, who maintains high approval among Republicans, had previously signaled he would remain active in politics.

Seven Republican senators voted to convict Trump on one article of inciting the Jan. 6 invasion of the Capitol, making it the most bipartisan impeachment trial vote ever. But the votes for conviction fell below two-thirds of the chamber, resulting in acquittal.

While McConnell voted "not guilty" in the impeachment trial, he has denounced Trump's conduct leading up to the Capitol riot. Minutes after the trial concluded, McConnell said on the Senate floor that Trump "is practically and morally responsible for provoking" the attack.

McConnell doubled down in an op-ed for The Wall Street Journal published Monday evening, slamming Trump's "unconscionable" behavior during and after the invasion while defending his vote for acquittal.

In his statement, Trump did not address the attack on the Capitol that led to his second impeachment.

A spokesman for McConnell's office did not immediately respond to CNBC's request for comment. But Josh Holmes, McConnell's former chief of staff, said in a tweet: "The most amusing part of this Trump letter is all the journos who told us Trump's words were dangerous and should be deplatformed are now wallpapering Twitter with them as soon as he attacks Republicans."

Trump, who lost the White House to President Joe Biden after a single term, blamed McConnell for losing Republican control of the Senate by pushing a too-small offer on direct payments in a coronavirus relief package.

"I single-handedly saved at least 12 Senate seats," Trump claimed, "and then came the Georgia disaster, where we should have won both U.S. Senate seats, but McConnell matched the Democrat offer of $2,000 stimulus checks with $600. How does that work?"

Trump spent the days before Georgia's Senate runoff elections spreading unfounded conspiracy theories that widespread fraud led to Biden's narrow win in the state. Shortly before those runoffs, news outlets published audio of a phone call showing Trump pressuring Georgia Secretary of State Brad Raffensperger to "find" the votes needed for him to win the state's presidential election. One attorney allied with Trump had also encouraged Republicans to boycott the runoffs.

Trump's statement also blamed Georgia's Republican governor, Brian Kemp, as well as Raffensperger and the Republican Party itself, for losing the Peach State runoffs. Trump appeared to resurface his false claims of election fraud by accusing those officials of "not doing [their] job on Election Integrity during the 2020 Presidential race."

Trump also accused McConnell of having "no credibility on China because of his family's substantial Chinese business holdings."

McConnell's wife, Elaine Chao, immigrated to the U.S. from Taiwan at a young age. She served as Trump's Transportation secretary until January, when she quit his Cabinet one day after the then-president's supporters stormed the Capitol.

A campaign ad from McConnell's former political opponent Amy McGrath had made a similar connection between McConnell's wealth and China. The Washington Post called that ad "grossly misleading," and McConnell's campaign called it racist.

Trump's statement also claimed that McConnell, who has won reelection every six years since 1990, would have "lost badly" without his endorsement. Trump said that providing that endorsement is his "only regret."