Donald Trump sat down with Bill O'Reilly for an interview before the Super Bowl. Getty

In a pretaped interview with Fox News pundit Bill O'Reilly that aired before the Super Bowl on Sunday, President Donald Trump appeared to draw moral similarities between the U.S. government and the authoritarian regime of Russian President Vladimir Putin.

The comments came after O'Reilly asked Trump if he respected Putin, and after the two presidents reportedly spoke on the phone on Saturday.

"I do respect him," Trump said. "Well, I respect a lot of people, but that doesn't mean I'm going to get along with them. He is a leader of his country. I say it's better to get along with Russia than not. And if Russia helps us in the fight against ISIS, which is a major fight, and Islamic terrorism all over the world ... that's a good thing.

"Will I get along with him? I have no idea. It's very possible I won't."

When O'Reilly pressed Trump to explain how he could respect Putin, who is "a killer," Trump pivoted to what seemed to be a comparison between Putin and former U.S. presidents.

"There are a lot of killers," said Trump. "What, you think our country's so innocent? You think our country is so innocent?"

When O'Reilly clarified that he didn't know of any government leaders who are killers, Trump didn't budge from his earlier comments.

"Well, take a look at what we've done, too. We've made a lot of mistakes. I've been against the war in Iraq since the beginning.

"A lot of killers around, believe me."

Senate leader Mitch McConnell, a top Republican, quickly criticized Trump's remarks on CNN's "State of the Union."

"I don't think there is any equivalency with the way the Russians conduct themselves and the way the United States does," McConnell said.

“[Putin] is a former KGB agent. He’s a thug. He was not elected in a way that most people would consider a credible election. The Russians annexed Crimea, invaded Ukraine and messed around in our elections.” McConnell said.

Rep. Adam Schiff, a Democrat who serves on the House Intelligence Committee, also condemned the comments.

"This is the second time Trump has defended Putin against the charge that he's a killer by saying in effect that the U.S. is no better or different," Schiff told CNN. "This is as inexplicably bizarre as it is untrue. Does he not see the damage he does with comments like that? And the gift he gives to Russian propaganda?"

"I want to know what the Russians have on Donald Trump," House Minority Leader Nancy Pelosi said on NBC's "Meet the Press."

"I think we have to have an investigation by the FBI into his financial, personal and political connections to Russia."