The New York Times and Associated Press report that, days before he was sacked, Comey had asked Rosenstein for more resources to pursue the investigation into Russian meddling in the 2016 presidential election.
White House press secretary Sean Spicer would neither confirm nor deny during Friday's press briefing that President Donald Trump has recorded audio of his private White House conversations, including his January dinner with ousted FBI Director James Comey.
A day later - which is to say, yesterday - during the White House press briefing, Sanders changed direction, saying the president wants the investigation to keep going.
Trump told NBC News that Comey had asked for the meeting because he wanted to stay on as FBI Director.
Thursday: "Oh, I was going fire regardless of recommendation. he made a recommendation, he's highly respected, very good guy, very smart guy, the Democrats like him, the Republicans like him, he made a recommendation but regardless of recommendation I was going to fire Comey", Trump said in an interview with NBC's Lester Holt. "That would be ideal".
Trump reiterated to Holt that he had been planning to fire Comey even before he received Deputy Attorney General Rod Rosenstein's recommendation to do so.
The White House disputed the Times's reporting.
Since the explosive decision was announced Tuesday, the president's advisers have struggled to come up with a consistent timeline and rationale. "The president has nothing further to add to that". "It's an excuse by the Democrats for having lost the election".
"In fact when I chose to just do it, I said to myself, I said you know, this Russian Federation thing with Trump and Russian Federation is a made up story", Mr Trump said. "The president chose to fire Director Comey".
Trump told NBC he had previously asked Comey whether he was under investigation in the Russian Federation matter, speaking with Comey once over dinner and twice by telephone. Second, he said that the investigation has all the resources it needs.
In his letter firing Comey on Tuesday, Trump wrote, "While I greatly appreciate you informing me, on three separate occasions, that I am not under investigation, I nevertheless concur with the judgment of the Department of Justice that you are not able to effectively lead the Bureau". Need it be repeated, the administration's case - that the director was sacked for his unprofessional actions towards Hillary Clinton - is risible.
"Yes, that's true", Trump said.
Later in the dinner, Mr. Trump again said to Mr. Comey that he needed his loyalty.
"We don't think it's necessary", said White House spokeswoman Sarah Huckabee Sanders.
Mr Comey, who testified for four hours before the Senate Judiciary Committee, said it made him feel "mildly nauseous" that his decision to make public his reopening of a probe into Mrs Clinton's handling of classified information might have affected the outcome of the 8 November presidential election.
Press aides have repeatedly insisted that Mr Trump chose to dismiss Mr Comey on the advice of Rod Rosenstein, the U.S. deputy attorney general. That makes it vital that others - the deputy attorney general, Congress and the press - act to control the damage to the country and the Constitution.