Sen. Elissa Slotkin (D-Mich.) on Wednesday declared that Donald Trump echoing pro-Russia propaganda and attacking Ukrainian President Volodymyr Zelenskyy marks a “really disturbing day” as the U.S. president looks to end Russia’s war in Ukraine.

Slotkin, a member of the Senate Armed Services Committee and Homeland Security Committee, told MSNBC’s Nicolle Wallace that Ukrainians are now seeing the U.S. “walking away” from defending democracy in favor of “siding with the aggressor, with the autocratic regime.”

“I can’t overstate how different this is in the post-World War II America and I think Ronald Reagan must be rolling over in his grave right now,” said Slotkin, who was part of a bipartisan delegation that recently met with Zelenskyy in Munich.

She continued, “To watch a Republican administration, after all he did to help us win the Cold War, now not only sort of supporting Putin’s position at the table but just sort of gushing over him in this bromance that they have.”

Trump falsely claimed that Ukraine “started” the war in 2022, which led Zelenskyy to declare that the U.S. president was in a Russian-made “disinformation space.”

Trump hit back by calling Zelenskyy a “dictator without elections,” comments that led some Republican lawmakers to stress that Russian President Vladimir Putin was the “evil” and “murderous” dictator.

Ukraine has been under martial law since Russia’s invasion of the country, thus suspending its elections.

Slotkin said the moves by Trump have made European allies “hedge” what they share with the U.S. and added that the Chinese government is “taking notes.”

“They’re looking and they’re basically saying, ‘America just doesn’t have the willpower to actually defend when a democracy is invaded, that’s important for us to know because maybe we’re interested in taking over a territory like Taiwan,’” she said.

“So I just think it’s not just about Ukraine, it’s about the signal it sends about America retreating from the world and being totally fine to cede leadership to places like Russia or China.”