President Biden doesn’t trust some of the Secret Service agents around him and doesn’t believe certain details of the biting incident with his dog Major, according to a new book about the administration.

Chris Whipple’s “The Fight of His Life: Inside Joe Biden’s White House” says Biden has trust issues with some agents, due in part to the fact that some agents are strong supporters of former President Trump.

“A bigger problem was Biden’s discomfort with his Secret Service detail; some of them were MAGA sympathizers. He didn’t trust them,” Whipple wrote, according to a copy of the book obtained by The Hill.

Biden’s detail as president is much larger than it was when he was vice president, and now many agents are “MAGA sympathizers” and, “The Secret Service is full of white ex-cops from the South who tend to be deeply conservative,” Whipple wrote.

The Secret Service response to the Jan. 6, 2021, attack on the U.S. Capitol after Trump tried to politicize the agency and made Tony Ornato deputy White House chief of staff for operations added to the president’s concerns.

“Surrounded by a new phalanx of strangers, Biden couldn’t help but wonder, Do these people really want me here?” Whipple wrote.

When the news broke that the Secret Service erased most messages from Jan. 6, along with revelations uncovered by the House panel that investigated the insurrection, Biden felt that the “Secret Service had looked both incompetent and politicized.”

There are also issues around the March 2021 incident in which Major, the president’s German shepherd rescue dog, allegedly bit a Secret Service agent. The president was reportedly skeptical about the Secret Service’s report of the situation.

Biden “wasn’t buying the details,” such as the location of the incident, although he didn’t dispute that the bite took place, Whipple wrote. Biden told a friend that Secret Service agents are never at the location of the incident, which was allegedly on the second floor of the White House.

“Somebody was lying, Biden thought, about the way the incident had gone down,” Whipple wrote.

Major, who is believed to be the first shelter rescue animal to live at the White House, received private training following the biting incident. Biden at the time defended Major and said he is a “sweet” animal simply adjusting to life in the White House alongside Secret Service details.

“The Fight of His Life: Inside Joe Biden’s White House” will be released on Jan. 17.