WASHINGTON (Reuters) -President Joe Biden on Wednesday threw his support behind the top U.S. military officer, Mark Milley, a day after a new book said he went around civilian leaders to place secret calls to his Chinese counterpart over concerns about then-President Donald Trump.

Milley’s Office disputed the claims in the book. They claimed that the phone calls he made while chairman of Joint Chiefs of Staff had been coordinated between the Pentagon and the U.S. government.

According to excerpts of the book, Milley secretly called General Li Zuocheng of the People’s Liberation Army twice in the final months of the Trump administration to say the U.S. government was stable. Milley told Li that the United States would not attack China, and that he would notify him in advance if there was an attack.

On Tuesday, the Washington Post published these excerpts.

Although there were concerns Milley might have subverted civilian control during the calls, Biden stood by him Wednesday.

Biden stated that he has great faith in General Milley.

Milley spokeswoman Colonel Dave Butler said that Milley called Chinese officials in October and January in accordance with his duty to “maintain strategic stability.”

Butler released a statement saying that “all calls by the Chairman from his counterparts including those reported” are being staffed, coordinated, and communicated to the Department of Defense (and the interagency). General Milley will continue to advise and act within the limits of his authority under the lawful tradition and civil control over the military, and in accordance with his oath.

The contents of these calls were not denied by Milley.

Milley was strongly supported by the Pentagon as well.

The Pentagon spokeswoman John Kirby (NYSE :), said that Milley was the Secretary of State and has full and utter confidence in him as the Chairman of the Joint Chiefs of Staff. However, he declined to comment on the allegations in the book.

The book, “Peril,” by journalists Bob Woodward (NASDAQ:) and Robert Costa, which they said relied on interviews with 200 sources, is due to be released next week.

Trump claimed that the story had been “fabricated” in a statement released Tuesday. He said Milley ought to be tried for treason if it were true.

Trump claimed, “For record, I have never thought about attacking China.”

Trump, a Republican named Milley the military’s top post in 2018, but began criticizing Milley and his appointees after he lost the November 2020 election to Biden.

Washington Post claims that Milley called the top military officers and asked them to look at the protocols for the launch of nuclear weapons. He said that only the president can give the order, but that he needed to participate.

Butler explained that Wednesday’s meeting about nuclear weapons protocols was held to remind uniformed Pentagon leaders of established and solid procedures, in light of reports on the topic.