A federal appeals court has ruled that President Donald Trump lacks the authority to build an $400 million ballroom at the White House, requiring Congressional approval. The US Court of Appeals for the District of Columbia Circuit sided with historic preservationists in their suit against the administration's plans for a 90,000-square-foot structure on the site where the East Wing once stood.

In response to the decision, President Trump wrote that he will appeal to the Supreme Court, describing the ruling as 'horrendous' and 'unlawful.' This setback follows another recent court ruling that suggested a proposed 250-foot arch could compromise historic landmarks within the Memorial Avenue Corridor.

The court’s 2-1 decision stated that Congress has full constitutional control over federal property, including its maintenance and development. In their opinion, judges cited 'the absence of any express or implied authorization' for the ballroom construction. They also noted that the demolition of the East Wing is unprecedented in American history.

The ruling does not affect a lower court decision that allowed the construction of a presidential bunker to continue. President Trump has claimed that the decision endangers the lives and welfare of White House workers, but the appeals court’s ruling leaves this aspect intact.