U.S. President Donald Trump on Wednesday said he did not fire James Comey "because of the phony Russia investigation," contradicting his 2017 statement that he ousted the FBI director last year over the probe.

"Both of those things can't be true," Comey said in response when asked about the president's comments on ABC, adding that he still does not know why Trump fired him last May.

"It matters that the president is not committed to the truth as a central American value," he said on the television network's "The View" program.