It immediately escalated the legal stakes - and the potential political damage - for a president who has tried to dismiss the matter as partisan witch hunt and a "hoax". Comey has long arms so Comey said he pre-emptively reached out for a handshake and grabbed the president's hand.
"Walls work. Just as Israel", Trump said, apparently referring to its West Bank barrier. Trump wrote on Thursday morning.
In his first press conference after Robert Mueller was named as special counsel for the Russian Federation investigation, Trump denied the allegations that have been lodged against him and called the speculation that he might be impeached "totally ridiculous".
It was a full flip-flop, going from absolutely "false" to "either confirming or declining to challenge almost every key aspect of the account", The Washington Post said.
It was emblematic of so many other dubious White House denials since he assumed office. The West Wing was leaking like a sieve and Mr. Trump was powerless to stop it. That was the White House's position initially after the deputy attorney general argued in a memo that Comey had erred in handling the FBI's investigation into Democratic nominee Hillary Clinton's private email server, even though Trump had praised Comey on the campaign trail previous year.
In that memo he accuses Mr. Trump of attempting to persuade him to shut down the FBI's investigation into his former national security adviser, Lt. Gen. Michael T. Flynn, who was sacked by Mr. Trump after admitting he lied about several contacts he had with the Russian ambassador to the U.S. "He is a good guy".
Several sources close to Flynn and to the administration tell The Daily Beast that Trump has expressed his hopes that a resolution of the FBI's investigation in Flynn's favor might allow Flynn to rejoin the White House in some capacity-a scenario some of Trump's closest advisers in and outside the West Wing have assured him absolutely should not happen...
"I hope you can see your way clear to letting this go, to letting Flynn go", Trump told Comey, according to the memo.
Today marked the first time since the appointment of a special counsel that Trump publicly addressed Comey's firing and the subsequent news of a memo written by the ex-FBI director.
Critics said Trump fired Comey as an effort to prevent embarrassing information from getting out.
Trump clearly knew what he wanted to say as he took a few questions at a news briefing with visiting Colombian President Juan Manuel Santos.
The allegation was made by Comey himself in a memo he wrote after a meeting in February.
As Mueller investigates the possible connections between the Trump campaign and Russian involvement in the 2016 election, these rumors will likely continue to swirl.
But this time he may have gone too far in his attempts to shut down the investigation into the widening Russian scandal that now threatens to bring down his presidency. But the move has fuelled speculation that the president sought to deliberately stall the investigation Comey was leading.
Mueller's appointment was not expected to affect the FBI or congressional investigations.
"Comey said that as he was walking across the room he was determined that there wasn't going to be a hug", Mr. Wittes said.