Washington (CNN)Michael Wolff, the author of a new exposé on President Donald Trump's first year in office, claims the 25th Amendment -- which addresses the transition of powers if a president is unable to execute his responsibilities -- was frequently discussed within the President's close orbit.
'Fire and Fury' author: 25th Amendment brought up 'all the time' in West Wing
"This is, I think, not an exaggeration, and not unreasonable to say, this is 25th Amendment kind of stuff," Wolff, author of "Fire and Fury: Inside the Trump White House," said in an interview on NBC's "Meet the Press." He said people in the West Wing brought it up "all the time."
"They would say ... we're not at a 25th Amendment level yet," Wolff said.
In the interview, Wolff did not provide information on the sourcing for his remarks; CNN has not independently confirmed all of the assertions in his book.
The White House has refuted the claims in the book since excerpts of it began to surface online ahead of its publication last week, with press secretary Sarah Sanders calling the book "complete fantasy" and a personal attorney for Trump sending a cease-and-desist letter to the author and publisher.
Trump has taken to Twitter to defend his mental abilities, calling himself a "very stable genius" on Saturday and writing Sunday that he has "had to put up with the Fake News" since announcing his candidacy. "Now I have to put up with a Fake Book," he wrote.
White House officials told NBC News that the last time Wolff spoke with the President was February 6, 2017, the network reported. However, Wolff said in the interview Sunday that "there were several other moments after that," although they were informal and Trump "probably did not think of them as interviews."
Wolff added that he did not violate any off-the-record agreements with sources.
Wolff told "Meet the Press" moderator Chuck Todd that he went into reporting on the Trump White House "with absolutely no agenda whatsoever."
"I have no particular politics when it comes to Donald Trump," he said. "This is really all about human nature."
Wolff added that when writing the book, he didn't remove any portions of text to serve a narrative.