President Trump attacked Michael Wolff calling him 'mentally deranged,' Saturday, just hours after the Fire & Fury author had to defend an attack on his credibility in an interview on CNN.

Trump tweeted Saturday: 'So much Fake News is being reported. They don't even try to get it right, or correct it when they are wrong. They promote the Fake Book of a mentally deranged author, who knowingly writes false information.'

The president added a parting shot at the media, in closing: 'The Mainstream Media is crazed that WE won the election!'

The president was lambasted for the tweet, which he sent during a day of golfing at Mar-a-Largo. He has not addressed an incident earlier in the day that saw Hawaiians running for their lives after an emergency alert erroneously went out about an incoming ballistic missile.

Just hours before the tweet, CNN's Michael Smerconish had a heated argument with Wolff in which the author accused the cable news host of doing the White House's work to 'discredit him.'

President Trump took a shot at Fire and Fury author Saturday, hours after Wolff was attacked on CNN

Trump tweeted the 'Fake Book' promoted by the 'Mainstream Media' hours after a CNN host got into a heated argument with the author- who in turn told the host he was doing the White House's work to 'discredit' him

In the exchange on CNN, Wolff had to defend a 'paper trail' between himself and a White House staffer, with the host seemingly quoting from an email exchange.

'What I'm really after is not so much a policy position interview with the president but an opportunity to humanize him,' Smerconish read, apparently quoting Wolff's email. 'I think you know that I like him, and I believe I can show him in a way that might actually change perceptions of him.'

Wolff first accused White House communications director Hope Hicks of providing Smerconish emails Wolff sent. He then retorted that the White House is 'totally incompetent' in its 'concerted attack' on the book.

Smerconish took particular issue with the idea that Wolff gained access to the White House, and people within, under false pretenses.

'When I write emails seeking interviews, my word choice is to say, ''I will treat the individual with dignity and respect.'' I never go so far as to say, ''Let me humanize. You know I like the person'' Smerconish told the author.

Wolff argued with Smerconish who had 'promised' the author the final word, when he did get what he wanted to say in, it was 'Read my book.'

Meanwhile: An emergency alert went out to people in Hawaii to take cover from a ballistic missile, which was sent erroneously. The president has not addressed the incident which saw Americans running for their lives

CNN's Michael Smerconish's heated exchange with Fire and Fury author Michael Wolff where engaged in a heated exchange Saturday morning as the host pressed him on how he went about gaining access to the White House staff

The tome, which the White House has repeatedly called fabricated, was an instant best-seller.

If the copies that are being printed and sent out now sell, Wolff stands to make a reported estimate of $7.4million, according to Bloomberg News.

And of course, he could always gain royalties if film producers seek to adapt all or part of his book into a film about the Trump administration.

Some of the sourcing has been called into question in Fire and Fury: Inside the Trump White House, however, many people on record have confirmed the quotes they had given to Wolff, including former White House chief strategist Steve Bannon.

Bannon, who saw the real fury of the White House when excerpts of the book were first release earlier this month, apologized for a single quote he gave about Donald Trump Jr.

In the book he called the infamous meeting between a Russian lawyer and lobbyist with Donald Jr. 'treasonous.' He issued an apology to the president's son, in which he stated 'Donald Trump, Jr. is both a patriot and a good man.'