A federal appeals court on Friday blocked President Donald Trump's $400 million plan to build a ballroom at the White House, ruling that the project needs congressional approval. In a 2-1 decision, the Washington-based US Court of Appeals for the District of Columbia Circuit halted construction on the ballroom, except for parts related to safety and security. The court upheld a preliminary injunction won by the National Trust for Historic Preservation, which sued last year over the project. The proposed 90,000-square-foot ballroom would be built on the site of the White House's demolished East Wing. The ruling is a major setback for Trump and a test of his presidential authority to manage the White House property without Congress's consent.