The White House has been on the defensive since excerpts of the book were published last week with the president and his aides scrambling to discredit both its portrayal of Trump and the author's methods.
"The author is a garbage author of a garbage book", said Miller, explaining that the depiction of the President was contrary to his own experience.
CNN's Jake Tapper, who was conducting the interview with White House Senior Adviser Stephen Miller, cut the conversation off after 12 and a half minutes, telling Miller he was spewing rhetoric exclusively to gain approval from the President.
On Twitter, Donald Trump said Miller had "destroyed" Tapper in the interview.
Throughout the interview, Miller repeatedly praised Trump's political prowess, knocking the "so-called political geniuses in Washington" who didn't predict the populist Republican's ascent.
Miller, in turn, scolded Tapper for making "condescending" and "snide" remarks and bashed CNN for airing "24 hours of negative, anti-Trump, hysterical coverage".
Corey Lewandowski, Mr. Trump's former campaign manager, said Mr. Bannon had clearly crossed a line.
"The book is best understood as a work of very poorly written fiction, and I also will say that the author is a garbage author of a garbage book", Miller said on CNN's "State of the Union" on Sunday. 'Watch the hatred and unfairness of this CNN flunky!'
Meanwhile, Trump's top policy adviser, on Sunday (Monday NZ Time) eviscerated Bannon over comments attributed to him in a new book, calling him an "angry, vindictive person" whose "grotesque comments are so out of touch with reality".
"I'm getting to the issue of your fitness", was Miller's riposte.
"Actually, throughout my life, my two greatest assets have been mental stability and being, like, really smart", the president said in a tweet.
"I regret that my delay in responding to the inaccurate reporting regarding Don Jr has diverted attention from the president's historical accomplishments in the first year of his presidency", Bannon said.
In a statement provided to the political website Axios, Bannon, who left the White House in August, said Trump's son, Donald Trump Jr. Tapper had to prematurey conclude the interview stating, "I think I've wasted enough of my viewers' time".
Speaking on NBC's "Meet the Press", Wolff said he was given access to the White House in the early months of Trump's term, and that his "goal was to keep going until somebody said go away". "You are being a factotum in order to please him".