Former national security advisor John Bolton said he doesn’t think President Donald Trump “fit for the office” during the ABC interview set to air Sunday night.

“I don’t think he’s fit for office. I don’t think he has the competence to carry out the job,” Bolton said. “There really isn’t any guiding principle that I was able to discern other than what’s good for Donald Trump’s re-election.”

Bolton further emphasized how Trump seemed to prioritize his re-election than the actual benefit of the country.

“So if he thought he could get a photo opportunity with Kim Jong Un at the Demilitarized Zone in Korea, there was a considerable emphasis on the photo opportunity and the press reaction to it and little or no focus on what such meetings did for the bargaining position of the United States,” he said.

Bolton’s bombshell tell-all book, The Room Where It Happened: A White House Memoir, is to be released on June 23. He is not the first former White House employee to release a tell-all book. Trump’s ex-lawyer Michael Cohen also revealed April that he is writing a book to expose Trump and will release it before the November election.

In response, Trump said on Twitter that the stories in Bolton’s book are just lies to discredit him.

“Bolton’s book, which is getting terrible reviews, is a compilation of lies and made up stories, all intended to make me look bad. Many of the ridiculous statements he attributes to me were never made, pure fiction,” Trump said. “Just trying to get even for firing him like the sick puppy he is!”