Comey said he wrote a memo immediately after the encounter because "I was honestly concerned that [Trump] might lie about the nature of our meeting, and so I thought it really important to document". "Totally illegal? Very 'cowardly!'" During his testimony, Comey said that he asked a "close friend" of his to leak the record of his conversations with Trump.
The president repeated that Comey's testimony had vindicated him of wrongdoing before adding "some of the things that he said just weren't true".
President Donald Trump drops a binder of environmental impact statements while delivering remarks on infrastructure investment and deregulation at the Department of Transportation on Friday.
"If there aren't tapes Trump should let that be known".
The Associated Press and USA Today contributed to the report. Comey said that Trump asked him specifically whether he could drop the investigation with respect to Flynn, the former national security adviser whom Trump fired for withholding information about his contacts with foreign governments.
He said that he'd carefully documented his interactions with Trump because he anxious Trump would misrepresent them, and accused the administration of spreading "lies, plain and simple" about the reasons for his firing.
But the former Federal Bureau of Investigation boss told the Senate panel he took meticulous notes of each meeting or conversation he had with Mr Trump because "I was honestly concerned that he might lie about the nature of our meeting, and so I thought it really important to document".
President Trump has a long history of threatening to file complaints and lawsuits and not following through.
An estimated 19.5 million viewers watched James Comey's widely televised U.S. Senate testimony.
Trump's pledge to offer sworn testimony to Mueller came in a press conference the day after Comey's testimony before the Senate intelligence committee.
The leaders of the House of Representatives intelligence committee said on Friday they've written to Mr Comey.