Corey Lewandowski says he knows of no one in Trump campaign who 'ever had a contact' with Russia

— -- A former campaign manager for President Trump said he knows of no one on the campaign who "ever had a contact with a Russian agent or a Russian affiliate."

Corey Lewandowski -- who served as Trump's campaign manager until he was fired in June 2016 amid reports of tension between him and campaign chairman Paul Manafort -- squared off on "This Week" Sunday with Hillary Clinton campaign manager Robby Mook on questions around Russia and Trump.

“I don't know of any person working on the campaign that ever had a contact with a Russian agent or a Russian affiliate or anybody that has to do with Russia. None whatsoever," Lewandowski told ABC News Chief White House Correspondent Jonathan Karl.

Karl pressed, "But you can't speak for Paul Manafort" or others?

Lewandowski replied, "Listen, I don't know what people do when they're not in my presence. I don't know what they're doing in their own private time. I can tell you that, unequivocally, I have never seen anybody who I have directed, or the president directed, ever reach out to someone from Russia. Never been instructed to do so ever. Never."

Manafort resigned from the campaign in the wake of scrutiny over his previous work as a lobbyist and political consultant in Ukraine.

Mook said on "This Week" that while he believes Lewandowski never reached out to Russia, “Paul Manafort’s connections to the Russians are clear. They paid him a lot of money to help get candidates elected that they wanted in the Ukraine. It’s not surprising to me that they might be trying to do the same thing in the United States.”

“What's particularly frightening to me about the situation is that these phone calls that Trump associates had with Russian agents were picked up because the [National Security Agency] taps these Russian agents regularly," Mook added. "This isn't speculation. These are phone calls that were actually picked up."

"What's also scary is that you saw the president kind of deflect the question [about possible contacts between people in his campaign and Russia]. He won't answer it. And the more we learn about this, the closer and closer it gets to President Trump,” Mook said.

Karl also asked about overall U.S. relations with Russia.

President Trump said at his press conference Thursday: "Does anybody really think that Hillary Clinton would be tougher on Russia than Donald Trump? Does anybody in this room really believe that, OK?"

Mook told Karl he "absolutely" thinks Clinton would have been tougher on Russia.

Referring to alleged Russian interference in the election, Mook said, "The reason Vladimir Putin did this is because Hillary Clinton spoke out against him ... And when Donald Trump has been asked about Vladimir Putin, he's praised him. He's called him a strong leader. Gave him an A rating."

But Lewandowski defended Trump's wanting to collaborate with Russia in fighting ISIS.

"Why, as the world's greatest superpower that we are, don't we want to work with another superpower to eradicate ISIS and ISIL in places where we have a common goal?" Lewandowski said. "Why isn't that a good thing? I'm missing it.”

Mook and Lewandowski also disagreed over the impact of Russian interference in the election.

"The problem is that Vladimir Putin devastates and destroys his enemies ... And Hillary Clinton spoke out against that. She had the courage to do that and she paid a price because Vladimir Putin interceded in this election," Mook said.

Lewandowski shot back, "Hillary Clinton did not lose this election because of Vladimir Putin. Hillary Clinton lost this election because she couldn't connect with females. She lost this election because the African-American vote was down from the historic proportion where it was four and eight years ago. Hillary Clinton did this because she was a terrible campaigner. They ran a terrible campaign. They lost in states that Democrats hadn't lost in 30 years. That's a fact."