The book's author, Michael Wolff, has also alleged that many people close to the President describe him as a "moron, an idiot" and that Mr Trump's deputy chief of staff said working with him is like "trying to figure out what a child wants".
"I absolutely spoke to the president".
In a tweetstorm Saturday morning, the president called himself a "very stable genius" and called being "really smart" one of his greatest assets.
"The truth is, over this period that I witnessed, this seven or eight months, they all came to the conclusion - gradually at first, then faster and faster - that something was unbelievably amiss here", Wolff said.
Rafael Nadal loses to Richard Gasquet at Kooyong Classic
It was the 12-time Grand Slam winner's first competitive outing since losing a Wimbledon quarter-final to Tomas Berdych last July. Former world number one Novak Djokovic faces a brutal challenge if he is to win the Australian Open in his comeback to tennis.
Bannon spoke out during a call-in segment of the "Breitbart News Tonight" radio show on Sirius XM hours after Trump's statement was issued, sharing kind words about the president.
Wolff's book has been heavily criticised by both Trump and Trump's supporters online, with the official GOP Twitter condemning the publication with its own satirical poster.
"Suddenly everywhere people are going 'Oh my God, it's true, he has no clothes.' That's the background to the perception and the understanding that will finally end... this presidency".
"In the initial airburst of revelations on Wednesday, Trump's "Make America Great Again" or "#MAGA" army dismissed the new stories as "fake news", but as the afternoon wore on, the tide turned against Bannon.
Press secretary Sarah Sanders said at Thursday's press briefing that Wolff made "at least two dozen requests" for an interview with the president which were never granted.
Líder nacional del PAN denuncia persecución del gobierno de Chihuahua
Durante la Primera Sesión Extraordinaria del Consejo Nacional, dejó en claro que el PAN "tiene mucho presente", pues ha logrado recuperar la confianza de la ciudadanía.
Trump's lawyers had tried to block publication of the book, however, the book has now gone on sale. According to the president, he never even gave him a quote.
Critics of the book accused Wolff of violating confidentiality agreements as well as reporting half-truths and outright lies.
The election of Donald Trump was a shot heard around the world.
"It's unusual for a book to get all this attention without anyone having known about it", said Bercu.
He told host Nick Robinson his story "seems to present this presidency in such a way that it says he can't do his job". She said Wolff "repeatedly begged to see the president" but was denied. Donald Trump, as we know, is prone to fits of rage.
Sensational book on President Trump is top seller online
The President described Mr Wolff as a "total loser who made up stories in order to sell this really boring and untruthful book". He wasn't fired, but Bannon's main financial backer is formally cutting ties with him, The Washington Post reported .