WASHINGTON: An appeals court on Friday upheld an order halting work on Donald Trump's prized White House ballroom, enraging the US leader and setting up another Supreme Court battle over the limits of presidential authority. It stayed its own decision for two weeks to give Trump time to ask the Supreme Court to intervene. The president vowed in a lengthy social media post to immediately appeal to the Supreme Court. Trump, who has repeatedly complained that the White House lacks sufficient space for grand galas such as state dinners, unilaterally ordered construction of the massive ballroom. Several of the projects have similarly faced legal challenges, but the ballroom project would be the first to reach the Supreme Court.