Fire and Fury: Trump says book is 'a work of fiction'

US President Donald Trump has hit out at a new book which raises questions over his mental health, calling it "a work of fiction".

Michael Wolff's book Fire and Fury: Inside the Trump White House, went on sale early on Friday amid the president lawyers' attempts to block its publication.

Mr Trump was asked for his thoughts on the book's allegations during a news conference at Camp David.