These reasons contradicted the White House's assertions - and even the widely-disseminated termination letter Trump sent Comey - that the dismissal was based on the recommendations of Attorney General Jeff Sessions and Deputy Attorney General Rod Rosenstein, who criticized Comey's handling of the email investigation into Hillary Clinton past year.
"James Comey better hope that there are no "tapes" of our conversations before he starts leaking to the press!" the president tweeted.
- Donald J. Trump (@realDonaldTrump) May 12, 2017When James Clapper himself, and virtually everyone else with knowledge of the witch hunt, says there is no collusion, when does it end? Or was it merely a button-pushing claim launched over frustration at news coverage of the controversy.
In another tweet on Friday morning, Trump again pointed to Clapper's testimony to call for an end to the Russian Federation investigation. The associate spoke on condition of anonymity to disclose details of a private conversation.
November 12, 2016: During a telephone call with top campaign donors, Clinton blames Comey for her defeat by Trump.
The White House schedule for Friday lists a 1:30 p.m. ET briefing to be conducted by White House Press Secretary Sean Spicer.
"I would note that NY is a one-party consent state, and President Trump has always abided by the law", said Sam Nunberg, a former campaign aide.
"We have got to make sure that these tapes, if they exist, don't mysteriously disappear", he said.
But it quickly became clear that the president had been stewing for days over the Russian Federation investigation and Comey's refusal to defend him in appearances before lawmakers.
"Even that is possible", he told reporters when asked whether he could announce his nominee by Friday, when he is scheduled to leave for the Mideast and Europe.
The president's advisers said this week that Trump fired Comey on Tuesday in response to a recommendation by Deputy Attorney General Rod Rosenstein.
"So I don't know if there was collusion or not", he continued.
On Thursday, Trump, discussing the firing of Comey, told NBC News that he was frustrated by the ongoing investigation and believed it was motivated by Democrats' fury at losing the election.
Even before Trump's provocative tweet, the White House was scrambling to clarify why Comey was sacked.
July 5, 2016: Republican presidential candidate Donald Trump calls the FBI's decision not to bring criminal charges against Clinton the greatest example yet that the system is "rigged".
Trump's recent comments have also prompted fresh accusations of interference with the FBI's Russian Federation investigation.
Indeed, the White House has released its own photos of the meeting, but none of them include Kislyak, even though he was clearly present according to the photos published by TASS, Russia's state-owned media agency. John Cornyn of Texas, attorney Alice Fisher and Judge Michael Garcia for the permanent position.
October 28, 2016: Trump reacts to FBI's decision to investigate new messages related to Clinton's emails, telling a campaign rally that he has "great respect for the Federal Bureau of Investigation for righting this wrong".
Calling Mr Trump's remarks about possible taped conversations "outrageous", senator Mark Warner of Virginia, the top Democrat on the Senate Intelligence Committee, said his panel or another congressional committee would "absolutely" subpoena the tapes.
Pearson and Lemire reported from NY.