US President Donald Trump has given his “100 per cent” commitment to tell his version of events under oath after former FBI director James Comey testified before the Senate panel looking into alleged ties between the White House and Russia.

At a White House press conference with Romanian President Klaus Werner Iohannis, Mr Trump rejected Mr Comey’s damning testimony at the Senate Intelligence Committee hearing on Friday (AEST).

During the hearing, Mr Comey re-asserted the US president asked him to drop the FBI’s investigation of former national security adviser Michael Flynnover Moscow’s alleged meddling in the US election.

Mr Comey claimed Mr Trump told him, “I expect loyalty”.

“He then said, ‘I hope you can see your way clear to letting this go, to letting Flynn go. He is a good guy. I hope you can let this go’,” Mr Comey claimed.

Asked if he was willing to give his side of the story, Mr Trump replied: “100 per cent”.

Reporters quizzed Mr Trump if Mr Comey had been “lying under oath”.

“Well, I will tell you I didn’t say that,” Mr Trump said before adding, “and there would be nothing wrong if I did say that according to everybody that I’ve read today.

“But I did not say that.”

Mr Trump also said he never asked Mr Comey for a pledge of loyalty.

“I hardly know the man. I’m not going to say ‘I want you to pledge allegiance’. Who would do that! Who would ask a man to pledge allegiance under oath?” he said.

Mr Trump also didn’t rule out the broad hint he dropped in one of his tweets that there might be audiotapes of his White House conversations with Mr Comey.

That suggestion has now been taken up by the House Intelligence Committee, which has written to Don McGahn, the White House counsel, and asked him whether White House recordings or memos of Comey’s conversations with Trump exist.

If they do, they asked that copies of the materials be provided to the panel by June 23.

“I’ll tell you about that, maybe sometime in the very near future,” Mr Trump told reporters gathered in the White House Rose Garden before moving on to questions about Romania.

On Twitter Mr Trump branded Mr Comey a “leaker” who could not be trusted.

Despite so many false statements and lies, total and complete vindication…and WOW, Comey is a leaker!

— Donald J. Trump (@realDonaldTrump) June 9, 2017

During the Senate Intelligence Committee, Mr Comey accused Mr Trump of lying to the American public when he sought to justify his dismissal as FBI director.

In the much-anticipated appearance, Mr Comey denied Mr Trump’s claims the FBI was in disarray and that he had lost confidence of agents.

“Those were lies, plain and simple,” Mr Comey said in his opening remarks ahead of the three-hour inquiry.

The FBI is one of the bodies investigating potential connections between Mr Trump’s 2016 campaign and allegations that Russia attempted to influence the outcome of the election.

Former FBI boss Bob Mueller has been appointed as a special counsel to oversee the Russia investigation.

Michael Flynn was sacked as National Security Adviser after it emerged he had lied to Vice-President Mike Pence over a meeting with Russian officials.

Mr Comey testified Mr Flynn was the target of a criminal investigation at the time he was fired, also confirming Mr Trump was not being directly investigated for alleged links to the Kremlin.