On Friday’s broadcast of NBC’s “Today,” “Fire and Fury” author Michael Wolff fired back at President Trump’s criticisms of Wolff’s book and stated that people around the president describe him as childlike.

Wolff reacted to the president’s attorneys sending him a cease and desist letter by stating that this not only drove up book sales, but proves the point of the book. He added that it is “extraordinary” that a president would try to stop a book’s publication, and another president wouldn’t do this.

The discussion then turned to Trump’s tweet about the book. Wolff said he “absolutely” spoke to the president for the book and spoke to those who had frequent contact with the president.

He later stated, “[O]ne of the things we have to count on is that Donald Trump will attack, he will send lawyers’ letters. This is a 35-year history of how he approaches everything.”

Wolff also said, “I have recordings. I have notes. I am certainly and absolutely, in every way, comfortable with everything I’ve reported in this book.”

Anchor Savannah Guthrie then asked, “Would you release any of those recordings since your credibility is being questioned?

Wolff responded, “My credibility is being questioned by a man who has less credibility than, perhaps, anyone who has ever walked on earth at this point.”

Wolff also responded to a negative profile of him that ran in the New Republic in 2004 that accused him of inventing stories by declaring, “I’ve written many books. I’ve written millions upon millions of words. I don’t think there has ever been one correction.”

After the discussion turned to the contents of the book, Wolff said that “100%” of the people around the president question his intelligence and fitness for office.

He continued that everyone described the president as like a child because of his need for instant gratification and the fact that “It’s all about him.”