President Donald Trump denied the reports, saying “China will not even be mentioned or discussed”.

Musk himself called for the prosecution of officials he said had leaked “maliciously false information” to the New York Times, which first reported the story.

But the Pentagon visit represented an unusual level of access for the Tesla and SpaceX CEO, whose companies hold billions of dollars in federal defence contracts.

As Musk departed the defence secretary’s office around 10:21 local time (14:41 GMT) on Friday, reporters asked him about the meeting.

“It’s always a great meeting. I’ve been here before, you know,” he said before departing the Pentagon.

The public back-and-forth about the meeting follows a New York Times report that Musk would learn about the China war plan during his Pentagon visit.

But NBC News and Politico later reported the Pentagon meeting would involve unclassified information.

An unnamed US official told Reuters that the briefing would be an overview of several topics that included China.

Trump said the New York Times reported “incorrectly, that Elon Musk is going to the Pentagon tomorrow to be briefed on any potential ‘war with China.’ How ridiculous?” China will not even be mentioned or discussed. How disgraceful it is that the discredited media can make up such lies. Anyway, the story is completely untrue!!!”

US Defence Secretary Pete Hegseth also denied the New York Times report, saying in a post on X “this is NOT a meeting about ‘top secret China war plans.’ It’s an informal meeting about innovation, efficiencies & smarter production”.

Musk’s visit to the Pentagon is drawing scrutiny over potential conflicts of interest.

Starlink and SpaceX, two of Musk’s companies, have contracts with the defence department. Tesla, his electric vehicle company, has two facilities in Shanghai, China.

Since Trump returned to the White House, Musk, as the head of the so-called Department of Government Efficiency (Doge), has been leading an outside effort to aggressively curtail government spending through funding cuts and firings.

Defence Secretary Pete Hegseth directed the move as one of his first acts in office, asking officials to investigate Gen Milley’s “conduct” and review his military grade.

Gen Milley previously served as the top US general during Trump’s first term but later criticised his former boss, and was quoted calling him a “fascist”.

Since returning to office, Trump has revoked security protections for a handful of former officials with whom he has clashed, including former top health official Anthony Fauci.

Trump previously accused Gen Milley of treason for phone calls he held with his Chinese counterpart during the final weeks of his first Trump presidency, including in the wake of a riot at the US Capitol building by Trump’s supporters in 2021.

Gen Milley reportedly used one of the calls to reassure China that the US would not launch a nuclear strike. On social media the president described those calls as “an act so egregious that, in times gone by, the punishment would have been DEATH!”.

Gen Milley, however, testified the calls were coordinated with other defence secretaries.

It was in Bob Woodward’s book War, published last year, that Gen Milley was quoted calling Trump “fascist to the core” and “the most dangerous person to this country”.

And in 2023, when giving his final speech as chairman of the joint chiefs of staff, Gen Milley said the military did not take an oath to a “wannabe dictator”. The comment that was seen by many as a reference to Trump, the man who nominated him for the job in the first place.

Ahead of Trump’s return to the White House last week, outgoing President Joe Biden issued Gen Milley – and a handful of others, including Fauci – a pre-emptive pardon in case they faced retribution from Trump.

Biden’s statement said the pardons should “not be mistaken as an acknowledgment” that any of those covered “engaged in any wrongdoing”.

Gen Milley thanked Biden for the move and said he did not want to spend the rest of his life “fighting those who unjustly might seek retribution for perceived slights”.

“I do not want to put my family, my friends, and those with whom I served through the resulting distraction, expense, and anxiety,” he said.

The news that Gen Milley was being stripped of his security detail and security clearance was confirmed in a statement to the BBC’s US partner, CBS News.

The Department of Defense Office of Inspector General has also been told to “conduct an inquiry into the facts and circumstances surrounding Gen Milley’s conduct so that the Secretary may determine whether it is appropriate to reopen his military grade review determination,” the statement said.

Trump’s new administration has also revoked security protections for his former Secretary of State Mike Pompeo, his former National Security Adviser John Bolton and his former envoy Brian Hook.

In the hours after Trump’s second inauguration, Trump’s officials also removed from the Pentagon a portrait depicting Gen Milley’s as chair of the joint chiefs of staff.