An upcoming book says Milley told General Li Zuocheng of the People’s Liberation Army that he would give him advance warning if President Donald Trump planned to launch a military attack against China. Trump and some Republican leaders have said that if the report is true, Milley may have committed treason.

“The Chairman of the Joint Chiefs regularly communicates with Chiefs of Defense across the world, including with China and Russia,” the Joint Staff spokesperson, Colonel Dave Butler, said in a statement. “These conversations remain vital to improving mutual understanding of U.S. national security interests, reducing tensions, providing clarity and avoiding unintended consequences or conflict.”

The accusations about Milley’s alleged conversations with Li come from the book Peril by Bob Woodward and Robert Costa, which is scheduled for release on September 21. In the book, the authors write that Milley spoke with Li twice in regards to concerns about Trump and a military strike.

The alleged first phone call came days before November’s presidential election, while the second alleged talk occurred on January 8, two days after the riot at the U.S. Capitol.

“General Li, you and I have known each other for now five years. If we’re going to attack, I’m going to call you ahead of time. It’s not going to be a surprise,” Milley told Li in one of their conversations, the authors write.

Butler said Milley’s calls “with the Chinese and others in October and January were in keeping with these duties and responsibilities conveying reassurance in order to maintain strategic stability.”

“All calls from the Chairman to his counterparts, including those reported, are staffed, coordinated and communicated with the Department of Defense and the interagency,” Butler added.

The spokesperson also said that “Milley frequently conducts meetings with uniformed leaders across the Services to ensure all leaders are aware of current issues” as part of “his responsibilities as senior military advisor to the President and Secretary of Defense.”

“The meeting regarding nuclear weapons protocols was to remind uniformed leaders in the Pentagon of the long-established and robust procedures in light of media reporting on the subject,” Butler said. He was referring to a January 8 meeting with National Military Command Center leaders in which Milley told them he had to be involved if there were any orders on a U.S. military strike, including a nuclear attack.

Butler concluded his statement by saying, “General Milley continues to act and advise within his authority in the lawful tradition of civilian control of the military and his oath to the Constitution.”