Rex Tillerson and John Kelly, two former top aides of United States President Donald Trump, tried to undermine him during their tenures in an effort to “save the country”, Nikki Haley, the former US ambassador to the United Nations, has claimed in her book With All Due Respect. The book will be released on Tuesday.

Tillerson was the secretary of state from February 2017 to March 2018, when Trump fired him. Kelly served as the White House chief of staff from July 2017 to January this year.

“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 wrote in her book, according to The Washington Post, which accessed a copy of the book. Haley held her post till December 2018 and was seen as a staunch Trump supporter.

“It was their decisions, not the president’s, that were in the best interests of America, they said,” Haley wrote. “The president didn’t know what he was doing.”

Haley claimed Tillerson had told her that people would die if Trump was left unchecked. The book describes Tillerson as “exhausting” and Kelly as suspicious of Haley’s access to Trump, according to The Washington Post.

Tillerson did not respond to the newspaper’s request for a comment on the claim. Kelly said that if providing the president “with the best and most open, legal and ethical staffing advice from across [the government] so he could make an informed decision is ‘working against Trump’, then guilty as charged”.

In an interview with CBS, Haley called Tillerson and Kelly’s attempt to subvert Trump “offensive”. “It should have been, go tell the President what your differences are and quit if you don’t like what he’s doing,” she said. “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. It was offensive.”

Meanwhile, Trump tweeted about the book with the message, “Make sure you order your copy today, or stop by one of her book tour stops to get a copy and say hello. Good luck Nikki!”

Trump had sacked Tillerson in March 2018 after a series of rifts over policy on North Korea, Iran and Russia. The relationship between the president and the former Exxon chief became strained after Tillerson reportedly called Trump a moron at a meeting at the Pentagon in July 2017 where other Cabinet members were present.