WASHINGTON — A federal judge who halted construction of President Donald Trump’s $400 million White House ballroom clarified on Thursday that the administration can proceed with below-ground construction of a bunker and other “national security facilities” at the site.

U.S. District Judge Richard Leon in Washington issued his latest ruling in a lawsuit over the ballroom project several days after an appeals court instructed him to reconsider the possible national security implications of stopping construction.

Government lawyers had argued that the project includes critical security features to guard against a range of possible threats, such as drones, ballistic missiles and biohazards.

Leon had barred work from proceeding without congressional approval, but he suspended enforcement of that order for two weeks. The appeals court extended that stay until Friday.