Author Michael Wolff claimed: "Donald Trump's marriage was perplexing to almost everybody around him - or it was, anyway, for those without private jets and many homes". Trump is to undergo at physical examination on January 12, the first of his presidency.
"Michael Wolff is a total loser who made up stories in order to sell this really boring and untruthful book", Trump wrote.
"He (Wolff) used Sloppy Steve Bannon, who cried when he got fired and begged for his job".
Trump tweeted Friday: "The Mercer Family recently dumped the leaker known as Sloppy Steve Bannon".
Wolff also addressed claims that Trump repeats himself and sometimes doesn't recognize old friends.
"When you write a book like this, people regret what they said to me". "They say he's a moron, an idiot".
On Brexit, although Mr Trump may not have recognised the term, he did - in the run-up to the referendum - say the UK would be better off outside the EU, even predicting a Leave victory. Asked what that indicates, Wolff said, "I will quote Steve Bannon: He's lost it".
"Let me accent that Â- anything". That's already a major hurdle. "But then there's the second hurdle that not only does he not read, he doesn't listen", he said.
The White House is pushing back against a book released Friday which is highly critical of the president.
Late last year, Attorney General Jeff Sessions told prosecutors to evaluate "certain issues" raised by congressional Republicans related to the Clinton Foundation, leading to speculation about the potential appointment of another special counsel. "You know I support him day in and day out". It quotes various right-leaning pundits and more objective journalists who are casting doubt on Wolff's reporting.
"I've never questioned his mental fitness".