United States President Donald Trump said on Sunday that the triumphal arch he plans to build near Arlington ​National Cemetery in Washington would double as a “military complex” housing drones and ‌snipers, as well as storing large quantities of ammunition.

The president cited national security concerns for the move, echoing the rationale offered for the roughly $400 million ballroom complex being built on ​the site of the White House’s former East Wing, which was ​demolished to make way for the project. He did not identify ⁠any specific threats.

The projects are part of Trump’s ambitious effort to reshape Washington, including a push to add his name to the John F. Kennedy ​Centre for the Performing Arts. The plans have drawn criticism from preservationists and others who argue they could alter or diminish historic landmarks.

In a social media post, Trump ​said that at the “strong request” of the military he had agreed to ​turn the 76-metre arch “into a top-grade Military Complex/Triumphal Arch, to house, store, and have ‌the ⁠rapid ability to use large numbers of drones, plus Snipers, on both the roof and plaza areas, and additionally have and hold large quantities of sniper ammunition in storage.”

The White House and the Department of Defence did not ​immediately respond to a ​request for comment.

The ⁠Federal Aviation Administration said last week that the arch would not pose a hazard to aircraft but would be required to have ​an “eternal flame” on top, clearing an aviation hurdle for ​the arch, ⁠which Trump proposed to mark the nation’s 250th anniversary.

Aviation experts have raised safety concerns given its proximity to Reagan Washington National Airport, while veterans have sued to ⁠block ​the arch, arguing it would destroy the historic ​sightline between the Lincoln Memorial and Arlington National Cemetery.