In her new memoir, former U.S. Ambassador to the United Nations Nikki R. Haley says that two of Donald Trump’s most influential advisers asked her to join an effort to undermine the president, the Washington Post reports.

The officials who approached her were Rex Tillerson, then secretary of state, and John Kelly, Trump’s chief of staff at the time, she claims.

Haley made the allegations in With All Due Respect: Defending America With Grit and Grace, which publisher St. Martin’s Press says “offers a first-hand perspective on major national and international matters, as well as a behind-the-scenes account of her tenure in the Trump administration.”

“Kelly and Tillerson confided in me that when they resisted the president, they weren’t being insubordinate, they were trying to save the country,” Haley writes in the book.

Haley repeated the claim on CBS News, adding, “To undermine a president is really a very dangerous thing. And it goes against the Constitution, and it goes against what the American people want. And it was offensive.”

Tillerson declined to comment to the Post about the allegations, while Kelly responded to CBS vaguely, saying, “If by resistance and stalling she means putting a staff process in place … to ensure [Trump] knew all the pros and cons of what policy decision he might be contemplating ... then guilty as charged."

With All Due Respect — Haley’s second book, following the 2012 memoir Can’t Is Not an Option— is slated for publication on Tuesday.

 Michael Schaub is an Austin, Texas-based journalist and regular contributor to NPR.