The White House has denied reports that President Donald Trump asked fired FBI Director James Comey to pledge loyalty to him.
Press secretary Sean Spicer rejected US media reports that the president sounded out Mr Comey at a private White House dinner in January.
According to the newspaper, the now-former FBI director said he would offer the president honesty, but not loyalty.
Mr Trump has faced a backlash for dismissing Mr Comey on Tuesday.
The FBI probe and parallel congressional investigations into alleged Russian political meddling, and whether any Trump campaign officials colluded with the Kremlin, have dogged his young presidency.
In Friday’s daily briefing, Mr Spicer refused to comment on questions about whether Mr Trump had been making surreptitious recordings in the White House.
Mr Trump tweeted hours earlier that Mr Comey had “better hope there are no tapes” of their conversations.
Mr Spicer denied the tweet was a threat.
“The president has nothing further to add on that,” he told reporters repeatedly when pressed about the post. “The tweet speaks for itself”.
However, Mr Comey believes “if there is a tape, there is nothing he is worried about”, a source told CNN.
Mr Trump’s comments provoked fresh comparisons between his administration and that of disgraced President Richard Nixon, who famously recorded conversations, speeding his downfall during the Watergate scandal.
The top Democrats on the House judiciary and oversight committees wrote to the White House on Friday demanding copies of any recordings.
John Conyers and Elijah Cummings’ letter noted “it is a crime to intimidate or threaten any potential witness with the intent to influence, delay or prevent their official testimony”.
‘Flooding the zone’: Analysis by the BBC’s Anthony Zurcher
Donald Trump was reportedly unhappy with how his press team handled fallout from Tuesday’s decision to fire Mr Comey, so he’s taken things into his own hands. Boy, has he.
First he gave an interview that essentially undercut all the arguments White House officials, from Vice-President Mike Pence on down, had made to paint the Comey sacking as an operation conducted through normal channels. Now he has taken to Twitter in earnest, spraying a barrage of allegations, accusations and aggressions against Democrats, the media and Mr Comey himself.
In sports terms, the strategy could be described as “flooding the zone” – launching a ferocious, full-out assault to overwhelm an opponent’s defences. In this case, Mr Trump has the media scrambling to decide which story merits the most coverage.
Is it the details of the Comey-Trump dinner and the president’s hints of secret “tapes”? His threat to cancel press briefings? The Oval Office visit by a Russian entourage? Perhaps, as Mr Trump suggests, the “real news” is the tentative trade agreement between the US and China on beef and poultry products?
When everything is a big story, nothing is. At least, that’s what Mr Trump may hope.
Mr Comey has declined an invitation to testify to the Senate Intelligence Committee next Tuesday.
President Trump told NBC News that Mr Comey requested the one-on-one dinner, but the former FBI director reportedly maintains it was the president who invited him.
Mr Comey had said he was “uneasy” before the dinner, according to former Director of National Intelligence James Clapper.
He told MSNBC on Friday that he had spoken to Mr Comey before the White House meal.
The FBI chief had confided he was concerned it might compromise his Trump-Russia inquiry, said Mr Clapper.
Mr Trump has said Mr Comey told him three times he was not a target of the FBI inquiry, fuelling accusations the president was interfering in the investigation.
Still chafing at media coverage of the firing, Mr Trump tweeted on Friday: “Maybe the best thing to do would be to cancel all future ‘press briefings’ and hand out written responses for the sake of accuracy???”
Mr Spicer said the president was a “little dismayed” that his press team’s attempts to give out information were being turned into a “game of gotcha” by the media.
Mr Trump doubled down in an interview with Fox News by threatening to hold the press briefings only once a fortnight, with himself at the podium.
“Unless I have them every two weeks and I do them myself, we don’t have them,” he said. “I think it’s a good idea. First of all, you have a level of hostility that’s incredible and it’s very unfair.”