"Fire and Fury: Inside the Trump White House" was rushed into bookstores and onto e-book platforms four days ahead of schedule due to what its publisher called "unprecedented demand" - and after Trump's bid to block it failed.
The book - which has sent shockwaves across Washington - quickly sold out in shops in the US capital, with some even lining up at midnight to get their hands on it. Trump has decried the instant best-seller as "phony" and "full of lies."
Journalist Michael Wolff, no stranger to controversy, quotes several key Trump aides expressing serious doubt about his ability to lead the world's largest economy - and despite fiery criticism from the Republican, he stood his ground.
"Let me put a marker in the sand here. One hundred percent of the people around him" question Trump's fitness for office, Wolff said in an interview with 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, who is approaching the first anniversary of his inauguration, has responded with fury to the claims in Wolff's book.
"I authorized Zero access to White House (actually turned him down many times) for author of phony book! I never spoke to him for book. Full of lies, misrepresentations and sources that don't exist," Trump tweeted Thursday.
But Wolff countered in Friday's interview: "I absolutely spoke to the president. Whether he realized it was an interview or not. I don't know, but it certainly was not off the record."
The book - which paints Trump as far out of his depth - includes extensive quotes from Steve Bannon, his former chief strategist, and his 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 by a series of his top aides.