The order blocks lower-court decisions that had paused work on the above-ground structure.

Chief Justice John Roberts broke with his fellow conservatives, joining the three liberal justices in dissent. He argued the project likely lacks legal footing since Congress never approved it, and warned the ruling undermines the balance of power between branches of government.

The case was brought by the National Trust for Historic Preservation, which argued Trump couldn’t authorise the build on his own. The dispute follows the demolition of the White House’s East Wing last autumn to make room for the 90,000-square-foot addition, which officials say should be largely done by November and finished by 2028.

The majority didn’t rule on whether the project itself is legal. Instead, they found the preservation group didn’t have standing to sue, and that the administration was likely to win its case while facing serious harm if the pause continued.

Trump celebrated the outcome online, calling the lawsuit meritless and predicting the ballroom will rank among the finest buildings ever raised in Washington.