A federal judge set new limits on President Donald Trump’s planned White House ballroom, saying construction could proceed only on an underground portion of the project deemed necessary by the military, and not on the 90,000-square-foot aboveground addition that Trump has eyed to entertain VIP guests.

“National security is not a blank check to proceed with otherwise unlawful activity,” U.S. District Judge Richard Leon wrote Thursday. He said the Trump administration could also take steps to secure the construction site to make it safe for people on the White House grounds, to protect the structural integrity of the building and to shield the underground work.

Leon chastised the Trump administration for its “incredible, if not disingenuous” interpretation of his order last month to halt work on Trump’s planned $400 million project until the president obtains authorization from Congress.

The judge’s original order allowed the White House to do further construction to ensure “the safety and security of the White House” after officials said work on an underground emergency bunker was necessary to protect the president, his family and his staff.

Trump, who had mischaracterized Leon’s earlier rulings as victories for the White House, attacked the judge Thursday on social media, calling him “a man who has gone out of his way to undermine National Security, and to make sure that this Great Gift to America gets delayed.”

“No Judge can be allowed to stop this Historic and Militarily Imperative Project,” the president wrote in a lengthy post on his Truth Social platform.

The president had previously argued that Leon’s order allowed him to keep building the ballroom, citing his plans to add bulletproof glass, bomb shelters and other security features to the building.

“This is positive for us,” Trump told reporters last month, insisting that work could continue – a claim echoed by Justice Department lawyers who swiftly appealed Leon’s ruling. A three-judge panel at the U.S. Court of Appeals for the D.C. Circuit last week asked Leon to clarify what parts of the project were paused before it rules on the case.

Leon, an appointee of President George W. Bush, rebuffed Trump’s argument, saying administration lawyers until recently had repeatedly told the court that the “above-ground and below-ground portions of the project were ‘independent of’ one another.”

“The fact that the ballroom is planned to include security features such as bulletproof windows and a drone-proof roof … may well be beneficial,” the judge wrote. But the administration has “not provided any national security justification for why these features must be installed immediately.”

The judge also wrote that he does not want to be continually consulted on whether aspects of the project can proceed.

“I have no desire or intention to be dragooned into the role of construction manager,” he wrote in his opinion.

He gave the Trump administration until April 23 to wrap up work before his pause takes effect. The administration has said it may appeal to the Supreme Court in a bid to continue construction.

Trump has said that the military is building a “massive complex” under the ballroom, but the administration has declined to offer details about the work. It has long been known that the area underneath the former East Wing contained secure facilities that the president and staff members could use in an emergency.

The National Trust for Historic Preservation, the organization that sued to block the ballroom construction last year, disputed Trump’s interpretation and asked Leon to explicitly bar any aboveground construction on the ballroom until it received authorization from federal panels and Congress. It also questioned the administration’s claim that pausing the project puts the president at risk.

“No matter how much the Defendants insist otherwise, the lack of a massive ballroom on the White House grounds is not a national-security emergency,” lawyers for the National Trust wrote in a filing Tuesday. They noted that Trump continues to live at the White House and entertain foreign dignitaries, despite the administration’s claim that the current situation poses a security risk.

The National Trust’s lawyers also called attention to the Justice Department’s shifting arguments over the project’s scope.

(c) 2026, The Washington Post · Dan Diamond, Jonathan Edwards