WASHINGTON D.C. — Republican Sen. Todd Young (R-Ind.) told reporters that he won’t be backing former President Donald Trump’s bid to return to the White House in 2024, citing the former president’s refusal to call Vladimir Putin a war criminal as one reason amongst seemingly several others.

“Where do I begin?” Young answered when pressed about his decision to not lend support.

Young spoke to reporters on Thursday, one day after Trump’s controversial appearance on a town hall hosted by CNN.

During the town hall, Trump continued to string together rants and parrot his standard lies that have repeatedly been proven false about a “rigged election” while stating that the rioters who stormed the Capitol on Jan. 6, 2021, “were there with love in their hearts.”

Trump also refused to call Russian President Vladimir Putin a war criminal while also declining to comment on whether he wanted Ukraine or Russia to win the war.

“I think President Trump’s judgment is wrong in this case,” Sen. Todd Young said. “President [Vladimir] Putin and his government have been engaged in war crimes. I don’t believe that’s disputed.”

Trump has often been criticized for his close ties to Putin and his soft stance on Russia.

The United States, meanwhile, has formally determined that Russia has committed crimes against humanity during its invasion of Ukraine. Some of these crimes include Russia targetting hospitals in bomb strikes, shooting civilians “in cold blood,” and Russian troops raping and assaulting women and children.

In March, the International Criminal Court issued an arrest warrant for Putin over alleged war crimes. Although the U.S. doesn’t recognize the jurisdiction of the ICC, President Joe Biden has gone on record stating that Putin should be tried for his war crimes.

“He is a war criminal,” Biden said. “This guy is brutal.”

Young’s break from Trump isn’t new as the Indiana Senator previously laid blame for the responsibility of the attack on the U.S. Capitol on Jan. 6, 2021, at the feet of the former president.

Young did not say who he would endorse as the Republican presidential candidate in lieu of Trump.