Comey's prepared remarks before the Senate Intelligence Committee highlighted awkward exchanges with Trump in which former head of the FBI said the president sought a vow of loyalty from him, and asked him to halt an investigation into a former top official.
During a Jan. 27 dinner, Comey said Trump demanded fealty, telling him: "I need loyalty, I expect loyalty.
"I didn’t move, speak, or change my facial expression in any way during the awkward silence that followed," Comey, who was unexpectedly fired last month, said. "We simply looked at each other in silence."
The tense exchange was followed roughly two weeks later by an Oval Office meeting in which Trump asked Comey to nix an investigation into Michael Flynn, Trump's former National Security Advisor who resigned in disgrace.
"He repeated that Flynn hadn’t done anything wrong on his calls with the Russians, but had misled the Vice President," Comey said in prepared remarks, referring to Trump. "He then said, 'I hope you can see your way clear to letting this go, to letting Flynn go. He is a good guy. I hope you can let this go.'"
The then FBI chief said he took those words "as a direction".
Comey described Flynn as being "in legal jeopardy" at the time Trump made the request.
The accounts of his meetings with Trump were based on memos Comey chose to write despite not doing so with two previous presidents he worked with, because he said, "I was honestly concerned that he might lie about the nature of our meeting.
"I knew there might come a day when I might need a record of what happened not only to defend myself but to protect the FBI,” he said.
After Trump made a veiled threat of taped conversations on Twitter, Comey said he sent the content of one of his memos to a reporter through an intermediary in hopes a special counsel would be appointed to lead the Russia probe.
The notes were later handed over to Robert Mueller, who was named special counsel last month.
Responding to Trump's threat that "Comey better hope that there are no 'tapes' of our conversations" Comey said Thursday, "Lordy, I hope there are tapes".
The bombshell revelations confirm rumored attempts from Trump to interfere in the FBI's independent operations at a time the bureau is probing possible collusion between the Trump campaign and a Russian attempt to tilt the outcome of last year's election in Trump's favor.
Comey is only the second FBI director to have his 10-year term cut short in the bureau's more than 100-year history.
When Comey found out he was fired -- from media reports -- he said he was confused by Trump's shifting explanations, and said the Trump administration "chose to defame me" and the FBI by using "lies, plain and simple".
Comey said he believed the Russia investigation played a role in his dismissal.