A day after James Comey accused him of lying, President Trump returned the favor Friday and said he would testify under oath to dispute the ex-FBI director's claims that Trump urged him to drop an investigation of former National Security Adviser Michael Flynn.

There was "no collusion, no obstruction" of justice, Trump said during a joint news conference with Romanian President Klaus Iohannis, adding that Comey is "a leaker" to boot. The "collusion" reference is apparently to the White House's long-running contention that there is no evidence Trump's campaign colluded with Russian attempts to undermine the election.

Trump flatly denied Comey's testimony that the president asked him to let go of an investigation into Flynn — "I didn't say that" — and denied the former director's claim that Trump asked him for a pledge of personal loyalty.

Asked if he would repeat his claims about Comey under oath, Trump said: "100%."

Tapes could resolve the dispute, but Trump against refused to say whether they exist, telling reporters he would do so "maybe sometime in the very near future."

Shortly after he fired Comey in May, Trump tweeted "James Comey better hope that there are no 'tapes' of our conversations before he starts leaking to the press!"

Echoing his attorneys and aides, Trump said the ex-FBI chief vindicated his claim that Comey told him on three occasions he was not under investigation over possible collusion with Russians who attempted to interfere with last year's election. While disputing Comey's testimony, Trump castigated the entire hearing as "just an excuse" for Democrats to blame their election loss on a false narrative about Russia.

Trump ignored a question on how he could accuse Comey of lying on one hand, and being truthful on the other.

Meanwhile, Democratic lawmakers and other critics say Comey's clams that Trump leaned on him to somehow drop the Russia investigation could amount to an obstruction of justice.

"I think he abused power," said House Minority Leader Nancy Pelosi, D-Calif. "Whether he obstructed justice remains for the facts to come forward."

Comey’s high-profile testimony also has turned part of the spotlight on Attorney General Jeff Sessions, who is expected to be questioned about Russia next week when he appears before a Senate Appropriations subcommittee.

Comey said a decision was made not report to Sessions a Feb. 14 White House meeting where Trump pressed the director to drop the FBI’s inquiry into Flynn, whom Trump fired for withholding information about his contacts with foreign governments. At the time, Comey said, the attorney general was weighing his recusal from all matters related to the Russia investigation — largely for his failure to acknowledge two previous meetings with the Russian ambassador during his January confirmation hearing — and for other “facts’’ the former director said he could not discuss publicly.

“We also were aware of facts that I can’t discuss in an open setting that would make (Sessions’) continued engagement in a Russia-related investigation problematic,’’ Comey told the Senate Intelligence Committee Thursday.

Contributing: Erin Kelly