Senate Minority Leader Chuck Schumer Sunday refused to "speculate" if President Trump obstructed justice in his conversations with former FBI Director James Comey about the Russia investigation.

But, the New York Democrat prodded Trump to publicly release tape recordings of those conversations, if they exist, and he invited the president to testify before the Senate.

"There is a cloud over the presidency, the president said, and that's rightly so," Schumer told John Dickerson, the host of CBS' "Face the Nation."

"There two ways to clear up that cloud," Schumer added. "If there are tapes, he should make them public right away. If there aren't, he [Trump] should let that be known. No more game playing. He said he would testify. I am inviting him to come testify and we can work that out."

House and Senate lawmakers leading the Russia investigation have asked the White House to provide tapes Trump hinted might exist of his conversations with Comey. The lawmakers also requested Comey to provide copies of the memos he said he wrote to chronicle the conversations.

In a news conference Friday, Trump said he would be "glad" to tell his side of the story to Special Counsel Robert Mueller, who the Department of Justice appointed to lead the Russia investigation. Trump said he would "100 percent" be willing to testify under oath that he never told Comey he hoped the FBI would stop investigating Mike Flynn, the president's first national security adviser.

Schumer accused Trump of not appreciating the seriousness of the Russia investigation, and challenged the president to be careful with his words — or to prove them correct.

"This is serious stuff, and the president seems to be taking this almost lightly," Schumer said. "When it comes to the tapes and it comes to testifying, he ought to say what he means. And if he does, we will take him up on each case."