“I hope you can let this go,” the president told Comey, according to the New York Times.
An associate of Comey’s who has seen the memo told Reuters that the details of the document as reported by the Times were accurate.
The White House quickly responded, saying it never asked Comey or anyone else to end the investigation into Flynn.
Comey, who was overseeing the probe into the Trump campaign’s ties to Russia, was fired by the president a week ago.
Flynn was fired by Trump after less than a month on the job. The White House said he misled Vice-President Mike Pence and other top officials about his communications with Russia’s ambassador to the United States.
*with a file from the Associate Press