But Comey has testified under oath that in a private meeting, Trump raised the investigation of fired national security adviser Michael Flynn - part of the larger Russian Federation probe - and said, "I hope you can see your way clear to letting this go, to letting Flynn go".
Trump seemed to confirm that he is under investigation on Friday morning when he criticized the special counsel's probe in a tweet.
In another tweet earlier on Friday, Mr. Trump wrote: "After 7 months of investigations & committee hearings about my 'collusion with the Russians, ' nobody has been able to show any proof".
Trump was referring to a memo prepared by Rod Rosenstein - and signed off on by Attorney General Jeff Sessions - that called for axing Comey because he, during the 2016 campaign, went around the department's chain of command.
His time under Bush, Obama and then Trump made him the longest-serving USA attorney in the nation's history when he was confirmed to his current role under Sessions.
The widened Russian Federation probe could have far-reaching repercussions for Trump's presidency, transforming his closest aides into witnesses and sucking even more political oxygen out of the West Wing.
Rosenstein took command of the investigation in early March, when Sessions announced that he was recusing himself due to his substantial role in Trump's presidential campaign a year ago.
That will only add to a sense of foreboding that pervades the White House, from the crammed collective workspaces of junior officials all the way to the Oval Office.
"Trump likely will become more unhinged as headlines dog him day after day, a parade of witnesses troop in to talk to the special counsel and the investigation metastasizes ...
Sad!" the president tweeted Friday.
Comey said he typed notes describing the conversations because he was anxious Trump "might lie" later about them. The order also demands that records be kept on any foreign travel by members of Trump's transition team and presidential campaign.
"Why is that Hillary Clintons family and Dems dealings with Russian Federation are not looked at, but my non-dealings are?" he asked at one point.
The Twitter attacks came as Vice President Mike Pence hired a personal lawyer to represent him in the intensifying investigation.