The Trump administration says stopping the $400 million White House ballroom project poses a national security threat. Officials told a federal appeals court that a judge’s order halting construction endangers the president, his family, and staff. Lawyers from the US National Park Service (NPS) filed a motion on Friday, saying the judge’s pause “threatens grave national-security harms” because the ballroom is planned as a heavily fortified facility. It will include bomb shelters, military installations, and a medical area. The project is part of Trump’s broader plan to quickly remodel the White House. “Time is of the essence,” the NPS lawyers wrote, stressing that materials for security installations must be installed promptly. US District Judge Richard Leon, nominated by former President George W. Bush, ordered a temporary halt to the project on Tuesday. The construction has involved demolishing part of the White House’s east wing. Leon said that unless Congress approves the project, preservationist groups challenging it are likely to succeed because no law clearly gives the president the authority he claims. Leon paused enforcement of his order for 14 days to allow the Trump administration to appeal. The ruling came after a key federal agency gave final approval for the project in the Washington region. The judge acknowledged potential logistical issues from stopping construction. He also reviewed confidential government information and concluded halting work would not jeopardize national security. Any essential construction necessary for the safety of the White House was exempted from the injunction. Trump criticized the judge’s order but noted that underground bunkers and other security measures can continue. These safety upgrades, however, will be paid for by taxpayers. Trump has pledged that he and private donors will fund the ballroom itself. The NPS motion emphasizes that the president has “complete authority to renovate the White House.” Officials say the current open construction site makes it harder to secure the property. The motion highlights that temporary canvas tents, intended for events without the ballroom, are vulnerable to drones, missiles, and other threats. In contrast, the planned ballroom is designed as a hardened national security facility. The Trump administration is asking the appeals court to rule on its request by Friday. It also wants the 14-day pause of Leon’s order extended by two weeks. This would allow the case to eventually reach the US Supreme Court. Lawyers argue that halting construction now could leave the White House exposed. They insist completing the ballroom and its security features is urgent for national safety. The dispute shows tensions between presidential authority, Congress, and preservationist groups. It also underscores the high stakes in balancing historic preservation with national security concerns. If the appeals court grants the motion, construction on the White House ballroom could resume while legal challenges continue. Meanwhile, Trump’s administration stresses that the project is crucial for the president’s protection.