Asked whether the White House has a recording of Comey's conversations with the president, Spicer said, "I am not aware of that." He also denied the tweet was a "threat," saying instead that the president had "simply stated a fact."
A week of contradictions from the White House
Friday's suggestion from the president caps a chaotic week for the White House, which has struggled to control the fallout after Comey's abrupt termination.
The presidential tweet appeared to be a response to news stories since the Tuesday firing, which have contradicted the White House's initial version of the events surrounding Comey's dismissal.
But in an NBC News interview on Thursday, it was Trump himself who said he was going to fire Comey regardless of the Justice Department's recommendation — even though White House staff and even Vice President Pence had pointed to the recommendation
from Deputy Attorney General Rod Rosenstein and Attorney General Jeff Sessions earlier in the week as the impetus for Trump's decision.
Senate Minority Leader Chuck Schumer, D-N.Y., announced Friday afternoon that Rosenstein has agreed to brief the full Senate next week in a closed-door session about Comey's dismissal and the FBI's Russia investigation.
Multiple outlets have reported that Trump asked Comey for his loyalty at a private dinner in January but that the then-FBI director "declined to make that pledge," The New York Times reported.
Spicer denied that Trump had asked Comey to pledge his loyalty during that dinner.
In an interview set to air Saturday night with Fox News' Jeanine Pirro, Trump said he didn't ask Comey for his loyalty but he didn't think it "would be a bad question to ask" and wasn't an inappropriate inquiry to the head of the FBI.
On MSNBC Friday afternoon, former Director of National Intelligence James Clapper told Andrea Mitchell that Comey had told him he was having dinner at the White House that evening in January and that he was "uneasy" over the invitation from Trump.
Congressional Democrats want "tapes" — and answers
The Senate Intelligence Committee had asked Comey to testify before it next Tuesday, but ranking member Mark Warner, D-Va., told MSNBC Friday that the former FBI director declined, although "it is our hope in the not too distant future that we can find a time for him to come in and talk to our committee."
"I believe at the appropriate time and place [Comey] is going to tell his side of the story, and my hope is that that place at least will be in front of our committee," Warner said.
It's unclear whether the "tapes" Trump alluded to in his tweet would be audio or video recordings, or whether they exist at all. As The Washington Post pointed out, the president used a similar construction in his unsubstantiated wiretapping accusations against former President Barack Obama.
Soon after Trump's tweets, Rep. Raja Krishnamoorthi, D-Ill., requested that White House Counsel Donald McGahn turn over any recordings of the president's conversations with Comey to the
House Oversight Committee. Krishnamoorthi also asked for any recording of Trump's Wednesday meeting
with Russian officials and "any conversations regarding the hiring or firing" of former national security adviser Michael Flynn.
"These White House tapes could accelerate current investigations as previous tapes have aided past inquiries," Krishnamoorthi said in a statement.
House Oversight Committee ranking member Elijah Cummings, D-Md., and House Judiciary Committee ranking member John Conyers, D-Mich., also sent McGahn a letter requesting any tapes or communications between Trump and Comey. The two also said they believed Trump may have intimidated a potential witness with his tweet, which is a federal crime.
"The President's actions this morning—as well as his admission yesterday on national television that he fired Director Comey because he was investigating Trump campaign officials and their connections to the Russian government—raise the specter of possible intimidation and obstruction of justice," Cummings and Conyers wrote in the letter. "The President's actions also risk undermining the ongoing criminal and counter-intelligence investigations and the independence of federal law enforcement agencies."
House Intelligence Committee ranking member Adam Schiff, D-Calif., also issued a blistering statement on Trump's tweets, calling on the president to "immediately provide any such recordings to Congress or admit, once again, to have made a deliberately misleading — and in this case threatening — statement."
Clapper pushes back against Trump's claims on Russia investigation
Trump also tweeted Friday morning that Clapper had testified there was no evidence of collusion between Trump's campaign and Russia — which the president deemed a "witch hunt."
On Monday, Clapper testified in a hearing on Russian election interference held by the Senate Judiciary Subcommittee on Crime
and Terrorism that he wasn't aware of any evidence of collusion and hadn't even been aware of the ongoing FBI investigation until Comey revealed it during a House hearing in March.
But Clapper later clarified to MSNBC that as DNI during the Obama administration he let FBI investigations operate independently and that such knowledge would be outside his scope.
"It is not surprising or ... abnormal that I would not have known about the investigation, or even more importantly, the content of that investigation," Clapper said. "So I don't know if there was collusion or not. I don't know if there was evidence of collusion or not. Nor should I have in this particular context."
Trump threatens to ax White House press briefings
In his Friday morning tweetstorm, the president also suggested that his administration could do away with briefings for the press and instead give out written statements.
Trump added that "as a very active president with lots of things happening," it's impossible for him to stay in such close communication with his staff that the briefings would be completely accurate.