U.S. President Donald Trump's lawyer is threatening legal action against former White House Chief Strategist Steve Bannon for making "disparaging" and "outright defamatory" statements in a new book. Those statements were made to Michael Wolff, the author of a book that chronicles Trump's first year in office. The president's attorney Charles Harder sent a letter to Bannon on Wednesday, demanding him to "cease and desist" any more of such claims.

In the book "Fire and Fury: Inside the Trump White House," Bannon was quoted as saying that a June 2016 Trump Tower meeting between the president's eldest son, Donald Jr., and a Russian lawyer was "treasonous" and "unpatriotic." Bannon also said there was "zero" chance that then-candidate Trump did not meet with the attendees at a later date or time. The book will hit shelves on Jan. 9 but excerpts of key sections were published on Wednesday. Trump, in a Wednesday statement, blasted Bannon. He said the former chief strategist had "not only lost his job" but also "lost his mind" when he left the White House. The president added that Bannon had little to do with his election victory and blamed him for the loss in the Alabama special U.S. senate election last month.

Former White House Chief Strategist Steve Bannon attends a ceremony at the White House April 10, 2017 in Washington, DC. Chip Somodevilla | Getty Images