Hundreds of generals and admirals, high-ranking commanders with a star or and his top advisers, have been summoned from around the world to the Marine Corps base in Quantico, Virginia, by Defense Secretary Pete Hegseth.
The person who spoke to the AP was not authorized to discuss the president's plans before his attendance was publicly announced and spoke on condition of anonymity.
News of the meeting broke Thursday, and Trump appeared unaware when first asked by reporters during an Oval Office appearance.
"I'll be there if they want me, but why is it a big deal?" the president said.
Trump's participation in the meeting increases the likelihood of a politicized event before a nonpartisan audience of military leaders, the AP said.
The White House had no immediate comment on Trump's attendance at the meeting.
