"We'll see what happens," he told reporters ahead of a speech to FBI's National Academy. "Let's see, I can say this: When you look at what's gone on with the FBI and the Justice Department, people are very, very angry."
Flynn pleaded guilty on Dec. 1 to lying to FBI agents. He is the first Trump White House official to officially get charged with a crime in special counsel Robert Mueller's Russia probe. Trump campaign chief Paul Manafort is among those also charged.
"For the record there is no consideration at all for a pardon for Michael Flynn at this time," the president's attorney Ty Cobb told NBC News Friday.
Flynn, who is cooperating with investigators looking into ties between Trump's top advisors and the Kremlin, is the closest link to the president to be flipped by law enforcement.
Trump has touted his ability to pardon aides in the past.
"While all agree the U. S. President has the complete power to pardon, why think of that when only crime so far is LEAKS against us," he wrote in a July post.
The Washington Post reported that Trump's lawyers were exploring the limits of the president's pardon authority over the summer. Trump attorney John Dowd called that report "nonsense."