Donald Trump says a newly released book containing damaging allegations about his administration is “full of lies”.
The book cites former top aide Steve Bannon as describing a meeting with a group of Russians at which Mr Trump’s son was present as “treasonous”.
It also portrays Mr Trump as being surprised by winning the presidency.
Mr Trump’s lawyers had tried to block publication of Fire and Fury: Inside the Trump White House by Michael Wolff, which has now gone on sale early.
The book is reportedly based on more than 200 interviews but some of the book’s excerpts have already been criticised and questioned.
Still, even if only half of what the book contains is true, it paints a damning portrait of a paranoid president and a chaotic White House, BBC North America editor Jon Sopel says.