Washington (CNN) A top White House aide called Steve Bannon's comments in a new book on President Donald Trump "grotesque" Sunday on CNN's "State of the Union" before anchor Jake Tapper cut him off for not answering questions.

"It's tragic and unfortunate that Steve would make these grotesque comments so out of touch with reality and obviously so vindictive," White House senior policy adviser Stephen Miller said, referring to Trump's former chief strategist.

During the contentious interview, Miller offered largely combative responses and focused on presenting Trump as a "political genius," repeatedly refusing to answer questions until Tapper decided to cut him off and move to the next segment.

CNN has not independently confirmed all the assertions in "Fire and Fury" by author Michael Wolff, which portrays Trump allies questioning the President's mental fitness for office.

Trump on Saturday took to Twitter to defend his mental abilities, saying he is "like, really smart" and a "very stable genius."

Read More