Sen. Rand Paul (R-Ky.) backed up President Trump in the face of harsh criticism from many Republicans over his surprise announcement that the 2,000-strong U.S. force will withdraw from Syria. 

In a tweet Wednesday morning and in a subsequent Twitter video, Trump claimed victory over ISIS, explaining that was "my only reason" for supporting a U.S. troop presence in the war-torn country.

The move was quickly blasted by Republicans, including Senators Lindsey Graham, Marco Rubio and Bob Corker, and Rep. Adam Kinzinger, who told Fox News he was "absolutely blown away" by the decision. 

Speaking on "America's Newsroom" Thursday, Paul said American voters were promised in 2016 that Trump would remove the U.S. from foreign entanglements. 

"It's one of the reasons he won the election," said Paul, arguing many Republicans want the U.S. to be "the world's policeman".

He said independent voters in places like Wisconsin, Pennsylvania and Ohio want to see spending on "America First," for border security and infrastructure, not foreign wars. 

Paul said the original goal of the U.S. deployment was to defeat ISIS and "99 percent" of the terror organization's territory has been reclaimed. 

"Ultimately, self-determination is about the people who live there standing up and fighting," he argued, saying it should not be the job of the American taxpayer. 

Trump's critics have also highlighted that the U.S. withdrawal is being praised by Russian President Vladimir Putin. 

"Donald is right, I agree with him," Putin said Thursday, arguing the U.S. troop presence was "illegal" because the Assad regime never approved it. 

Watch the full interview above. 

On "Fox News @ Night" Wednesday, Sen. Mike Lee (R-Utah) disagreed with those who argue Trump's withdrawal is an "Obama-like decision."

He said officials, going back to the Obama administration, could never explain a clear objective for U.S. troops fighting in Syria and Congress never approved the deployment. 

Watch the interview below. 

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