Journalist Michael Wolff, the author of a controversial tell-all book on the administration of President Donald Trump, said Friday on NBC's "Today" show that "100 percent of the people" around the president question his ability to lead.

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“Senior advisers, family members, every single one of them, questions his intelligence and fitness for office,” Wolff said.

"Fire and Fury: Inside the Trump White House," was released Friday, one day after an attorney for the president sent a cease and desist order to Wolff and the book's publisher after excerpts from it painted an unflattering picture of Trump and his administration.

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Among other claims, Wolff wrote that Trump didn’t want to win the presidential election, got angry over celebrity snubs at his inauguration and eats fast food partially because of his fear of being poisoned.

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"I will tell you, the one description that everyone gave, everyone has in common: They all say he is like a child," Wolff said Friday on the "Today" show. "And what they mean by that is, he has a need for immediate gratification. It is all about him."

Wolff said “Fire and Fury” was cobbled together from 18 months’ worth of conversations with Trump and senior staff members and more than 200 interviews. He stood by the statement Friday, despite a tweet from the president Thursday night in which Trump said he never gave Wolff access to the White House or spoke with him.

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Instead, Trump said, the book was filled with “lies, misrepresentations and sources that don’t exist.”

Wolff insisted Friday that he spoke with the president and his staff members.

"My credibility is being questioned by a man who has less credibility than, perhaps, anyone who has ever walked on earth at this point," Wolff said on the "Today" show. "I work like every journalist works, so I have recordings. I have notes. I am certainly and absolutely in every way comfortable with everything I've reported in this book."

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White House press secretary Sarah Huckabee Sanders on Thursday denied allegations made in Wolff’s book, calling it a “complete fantasy and just full of tabloid gossip.”

It's not the first time Wolff's credibility has come into question. According to The Washington Post, he was accused of making up quotes and fabricating scenes in his 1998 book "Burn Rate" and in columns he wrote while working for New York magazine.

In this April 12, 2017, file photo, Michael Wolff of The Hollywood Reporter speaks at the Newseum in Washington.
 (AP Photo/Carolyn Kaster, File)

Credit: Carolyn Kaster

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Credit: Carolyn Kaster