He also claimed Mr Comey's comments failed to prove any collusion
US President Donald Trump has accused former FBI director James Comey of lying under oath to Congress, and dismissed his testimony as politically motivated.
He also claimed that Mr Comey's comments to the Senate Intelligence Committee failed to prove any collusion between the Trump campaign and Russia.
"Yesterday showed no collusion, no obstruction," Mr Trump said in the White House Rose Garden during a news conference with the Romanian president, Klaus Iohannis.
"That was an excuse by the Democrats, who lost an election they shouldn't have lost," he said.
"It was just an excuse, but we were very, very happy, and, frankly, James Comey confirmed a lot of what I said, and some of the things that he said just weren't true."
President Trump denied asking Mr Comey for his loyalty: "I hardly know the man. I'm not going to say 'I want you to pledge allegiance'. What would do that?
"Who would ask a man to pledge allegiance under oath? Think of that. I hardly know the man."
The president later said he would "100%" be willing to testify under oath.
But Donald Trump refused to say whether his private conversations with the fired FBI Director were taped - an issue at the centre of conflicting accounts of what passed between them.
"Well, I'll tell you about that - maybe sometime in the very near future," Mr Trump said. "I'm not hinting anything."
"Oh you're going to be very disappointed when you hear the answer, don't worry," he added.
US House and Senate investigators have now fired off requests for both Mr Comey's memos and any recordings the White House kept of his private meetings with President Trump.
The committee want the material by June 23rd.
A friend of Mr Comey's is also being asked to hand over memos the former FBI chief gave him.
Mr Comey testified that he had given a memo, including details about a conversation with President Trump, to a friend - who was later identified as law professor Daniel Richman.
During Thursday's hearing, Donald Trump was unusually silent on social media, even as Mr Comey accused his administration of spreading lies.
But the following morning he struck back in an early morning tweet: "Despite so many false statements and lies, total and complete vindication," he wrote - suggesting Mr Comey had committed perjury.
Mr Trump also seized on Mr Comey's revelation that he had directed a friend to release memos documenting his conversations with the President to a reporter: "...and WOW, Comey is a leaker!" he tweeted.
Despite so many false statements and lies, total and complete vindication...and WOW, Comey is a leaker!— Donald J. Trump (@realDonaldTrump) June 9, 2017