The Trump administration urged a federal judge not to block construction of the White House ballroom, arguing that stopping the project midstream would create security risks at the executive mansion and force an emergency appeal.

In a late-day filing on Monday, the Justice Department asked U.S. District Judge Richard Leon to stay any injunction he might issue against the East Wing modernization and ballroom project, warning that a halt would disrupt Secret Service operations and leave an exposed excavation site in President’s Park. The government said the project is “imperative for reasons of national security” and cannot be safely paused in part.