President Trump disclosed Sunday that the U.S. military is constructing an underground complex beneath a planned new White House ballroom, revealing details about the project during remarks to reporters aboard Air Force One.

"Now, the military is building a big complex under the ballroom, which has come out recently because of a stupid lawsuit that was filed," Trump told reporters. The president indicated that information about the underground construction had become public through legal proceedings.

The $400 million White House ballroom project has received approval from the Commission of Fine Arts, according to Trump's previous statements. The president has indicated that private donors would fund the ballroom construction.

Trump described the underground portion as a "massive complex" being built by military personnel, though he provided few additional details about the facility's specific purpose or scope during his Air Force One remarks.

The revelation comes amid ongoing discussions about White House security enhancements and facility improvements. The timing of Trump's disclosure appears linked to recent legal challenges that have brought aspects of the project into public view.