A federal appeals court has ruled that President Donald Trump’s administration must stop construction of the $400 million White House ballroom because Congress has not approved the project. Trump blasted the decision Friday as “unjust” while vowing to appeal it to the U.S. Supreme Court. A three-judge panel of the U.S. Court of Appeals for the District of Columbia circuit ruled that Trump doesn’t have the unilateral authority to build a 90,000-square-foot ballroom where the East Wing stood before he ordered its demolition. The panel upheld an April order from a lower court judge for aboveground work on the project to be halted.