Reuters

US Sectary of State Rex Tillerson found himself obliged to defend President Donald Trump’s fitness for office Friday after a bombshell new book called into doubt his mental health.

In an extraordinary portion of a television interview on foreign policy challenges, Tillerson was asked about claims that Trump has a short attention span, regularly repeats himself and refuses to read briefing notes.

“I’ve never questioned his mental fitness. I’ve had no reason to question his mental fitness,” said Tillerson, whose office was last year forced to deny reports that he had referred to Trump as a “moron” after a national security meeting.

And, even in defending Trump, the former ExxonMobil chief executive admitted he has had to learn how to relay information to a president with a very different decision-making style.

“I have to learn how he takes information in, processes it and makes decisions,” Tillerson told CNN. “I’m here to serve his presidency. So I’ve had to spend a lot of time understanding how to best communicate with him.”

But Tillerson emphasised the right decisions had been made and that the United States is in a stronger place internationally thanks to Trump’s policies.

“He is not a typical president of the past, I think that’s well recognised — that’s also why the American people chose him,” he said, insisting that he does not expect to be asked to resign in the coming year.

Tillerson was forced to mount his defence as Washington devoured a new supposed tell-all — Michael Wolff’s “Fire and Fury: Inside the Trump White House” — rushed into bookstores after the White House failed to suppress it.

The book quickly sold out in shops in the US capital, with some people even lining up at midnight to get their hands on it and others circulating pirated copies. Trump has decried the instant best-seller as “phony” and “full of lies.”

Journalist Wolff, no stranger to controversy, quotes several key Trump aides expressing doubt about Trump’s ability to lead the world’s largest economy and military hegemony.

“Let me put a marker in the sand here. One hundred percent of the people around him” question Trump’s fitness for office, Wolff told NBC’s “Today” show.

“They all say he is like a child. And what they mean by that is he has a need for immediate gratification. It’s all about him.”

The 71-year-old Republican president, approaching the first anniversary of his inauguration, has responded to the book with fury.

“I authorized Zero access to White House (actually turned him down many times) for author of phoney book! I never spoke to him for book. Full of lies, misrepresentations and sources that don’t exist,” Trump tweeted Thursday.

But Wolff countered: “I absolutely spoke to the president. Whether he realised it was an interview or not, I don’t know, but it certainly was not off the record.”

The book includes extensive quotes from Steve Bannon, Trump’s former chief strategist, and its publication sparked a very public break between the former allies.

Bannon is quoted accusing Trump’s eldest son Don Jr of “treasonous” contacts with a Kremlin-connected lawyer, and saying the president’s daughter Ivanka, who imagines running for president one day, is “dumb as a brick.”

But it is Trump himself who is cast in the most unfavorable light.

Late Friday Trump fired another bitter tweet, calling Wolff “a total loser who made up stories in order to sell this really boring and untruthful book.”

“He used Sloppy Steve Bannon, who cried when he got fired and begged for his job. Now Sloppy Steve has been dumped like a dog by almost everyone. Too bad!”

The book claims that for Treasury Secretary Steve Mnuchin and former White House chief of staff Reince Priebus, the president was an “idiot.” For chief economic advisor Gary Cohn, he was “dumb as shit.” And for National Security Adviser H.R. McMaster, he was a “dope.”

Get more stories like this on Twitter & Facebook

AD: To get thousands of free final year project topics and other project materials sorted by subject to help with your research [click here]