Trump doesn't back down from slamming tell-all, calling author a 'total loser,' the book 'boring'

The president also continued to refer to Steve Bannon as 'Sloppy Steve.'

"Michael Wolff is a total loser who made up stories in order to sell this really boring and untruthful book," Trump wrote of the book, which hit bookstores Friday. "He used Sloppy Steve Bannon, who cried when he got fired and begged for his job. Now Sloppy Steve has been dumped like a dog by almost everyone. Too bad!"

Wolff joins a club of "total losers" -- foes of the president who he's described as such -- including Mark Cuban, Cher, Rosie O'Donnell and Seth Meyers.

“Whether he realized it was an interview or not, I don't know," Wolff said of Trump on the "Today" show. "But it certainly was not off the record.”

The author said he spent three hours with Trump including over the course of the campaign and in the White House after the inauguration.

"My window into Donald Trump is pretty significant," Wolff said.

Trump introduced the nickname "Sloppy Steve" in a tweet Thursday night, writing "I authorized Zero access to White House (actually turned him down many times) for author of phony book! I never spoke to him for book. Full of lies, misrepresentations and sources that don’t exist. Look at this guy’s past and watch what happens to him and Sloppy Steve!"