The former FBI director said Trump "lies constantly about matters big and small" and "treats women like they're pieces of meat"
The former FBI director James Comey has described Donald Trump as 'morally unfit' to be US president, saying he 'lies constantly'.
Mr Comey was fired by President Trump last year, and his book A Higher Loyalty - which has already become a bestseller - is being published this week.
Ahead of the book's launch, Mr Comey spoke to ABC News in a highly-anticipated interview.
Mr Comey said he doesn't agree with any suggestion that President Trump is 'mentally incompetent or [in] early stages of dementia', saying: "He strikes me as a person of above average intelligence who's tracking conversations and knows what's going on."
However, he added: "I don't think he's medically unfit to be president. I think he's morally unfit to be president."
The former FBI chief observed: "A person who sees moral equivalence in Charlottesville, who talks about and treats women like they're pieces of meat, who lies constantly about matters big and small and insists the American people believe it... that person's not fit to be president of the United States, on moral grounds."
Should Pres. Trump be impeached?— ABC News (@ABC) April 16, 2018
.@Comey: "Removing Donald Trump from office would let the American people off the hook, and have something happen indirectly that I believe they're duty bound to do directly. People in this country need to stand up and go to the voting booth." pic.twitter.com/Rfo4ePgQM8
Mr Comey said he has described Donald Trump in the book as a 'forest fire' who will cause 'tremendous damage', but also struck a note of optimism in his suggestion that a forest fire "gives healthy things a chance to grow that had no chance before that fire".
He argued: "I see the kids marching in the streets, including my own kids, about guns. I see all kinds of civil society getting engaged. I see parents talking to their kids about truth telling and prejudice and bias and respect.
"That was not happening three or four years ago. And so there's a lot of good growing."
Donald Trump repeatedly hit out at Mr Comey in the lead-up to the interview, describing him as an 'untruthful slime ball'.
Slippery James Comey, a man who always ends up badly and out of whack (he is not smart!), will go down as the WORST FBI Director in history, by far!— Donald J. Trump (@realDonaldTrump) April 15, 2018
I never asked Comey for Personal Loyalty. I hardly even knew this guy. Just another of his many lies. His “memos” are self serving and FAKE!— Donald J. Trump (@realDonaldTrump) April 15, 2018