Former FBI director James Comey has said Donald Trump is "morally unfit to be president", who treats women like "pieces of meat, BBC reports.
Mr Comey was giving his first major television interview since he was fired by President Trump last year.
He told ABC News that Mr Trump lies constantly and may have obstructed justice.
Hours before the interview aired, the president went on the offensive, accusing Mr Comey of "many lies".
Mr Comey told ABC's 20/20 programme on Sunday night: "I don't buy this stuff about him being mentally incompetent or early stages of dementia."
"I don't think he's medically unfit to be president. I think he's morally unfit to be president.