WASHINGTON, March 20 (Reuters) - U.S. President Donald Trump has denied a New York Times report that his close ally, billionaire Elon Musk, was due to be briefed by the Pentagon on Friday about the U.S. military's plan for any war that might break out with China.

"China will not even be mentioned or discussed," Trump said in a post about the Pentagon meeting on Truth Social on Thursday.

Pentagon chief Pete Hegseth said in a post on X that the meeting would be "about innovation, efficiencies & smarter production."

A U.S. official, speaking on the condition of anonymity, said the briefing for Musk would be attended by senior U.S. military officials in the Pentagon and would be an overview on a number of different topics, including China.

According to the New York Times report, the briefing would include 20 to 30 slides that lay out how the United States would fight in a conflict with China. The newspaper cited two U.S. officials it did not identify.

Access to the closely guarded military plan would mark a sharp expansion of Musk's role as a Trump adviser who has spearheaded efforts to cut U.S. government spending.

It would also fuel questions about conflicts of interest for Musk, who as the head of Tesla and SpaceX has business interests in China and with the Pentagon.

The White House has previously said Musk will recuse himself if any conflicts of interest arise between his business dealings and his role in cutting federal government spending.

Washington and Beijing have had tense relations for years over differences ranging from access to technology, trade tariffs and cybersecurity to TikTok, Taiwan, Hong Kong, human rights and the origins of COVID-19. (Reporting by Phil Stewart, Idrees Ali and Kanishka Singh in Washington; Editing by Stephen Coates and Edwina Gibbs)