Sen. Bernie Sanders took to Twitter Thursday to blast former President Donald Trump and his recent praise of Russian President Vladimir Putin, calling it "outrageous, if unsurprising."

"It is outrageous, if unsurprising, that Trump would praise Putin’s murderous invasion of Ukraine as an act of ‘genius,’" Sanders tweeted. "It should concern us all that Putin is exactly the kind of leader Trump would like to be, and that so few Republicans have the courage to say this out loud."

The Vermont senator’s post came just hours after Putin invaded Ukraine on Thursday morning. 

Bernie Sanders and Donald Trump. 

Bernie Sanders and Donald Trump.  (Reuters)

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Sanders’ comments come after Trump seemed to compliment Putin during an interview on "The Clay Travis and Buck Sexton Show" Tuesday.

During the interview, Trump called Putin "savvy" and said his decision to invade Ukraine was "genius." 

Former President Donald Trump pauses as he speaks at a rally Saturday, Jan. 15, 2022, in Florence, Ariz.

Former President Donald Trump pauses as he speaks at a rally Saturday, Jan. 15, 2022, in Florence, Ariz. (AP Photo/Ross D. Franklin)

"I said, 'How smart is that? He's going to go in and be a peacekeeper,'" Trump said. "That's the strongest peace force. We could use that on our southern border. That's the strongest peace force I've ever seen. There were more army tanks than I've ever seen. They're going to keep peace, all right."

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In a series of tweets, Sanders also called on the U.S. and international partners to impose sanctions against Russian and to stand up against its "corrupt, reckless president."

"What the whole world is seeing today is nothing less than a blatant violation of international law and of basic human decency," the senator said. "This war will likely kill thousands of people and create millions of refugees."

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"This aggression is unacceptable," Sanders added. "Today, I hope all of us will stand with the Ukrainian people against this war and with the Russian people who are demonstrating against their own corrupt, reckless president who started it."