The US appeals court has blocked Donald Trump's $400m (£297m) White House ballroom.
The federal appeals court ordered the Trump administration to stop construction of the ballroom on the site of the White House's demolished East Wing.
The Washington-based US Court of Appeals for the District of Columbia Circuit upheld a preliminary injunction won by the National Trust for Historic Preservation.
Last year the non-profit sued after the administration tore down the East Wing and began building a 90,000 sq ft (8,360-square-meter) ballroom without authorisation from Congress.
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The judge also paused the block on the project for 14 days to allow the Trump administration to appeal the decision to the US Supreme Court.
Trump had appealed after US District Judge Richard Leon twice blocked above-ground construction on the site while allowing underground work to continue.
Leon, appointed by Republican former President George W. Bush, had ruled that no federal statute "comes close to giving the President" the required authority to construct the ballroom without congressional approval.
The administration says the plan is necessary for large formal functions and to preserve the safety of the White House.
It is the grandest of Trump's efforts to reshape central Washington's landscape of government buildings and national monuments.
Justice Department attorney Yaakov Roth said during D.C. Circuit arguments on 5 June that the courts have no role in weighing the privately funded project and that it would have been improper to block it at any point.
Mr Roth said the National Trust's "architectural preference" against the ballroom should not take precedence over national security concerns, claiming evidence that the former East Wing left the president and others in the White House vulnerable to attack.
But Thaddeus Heuer, a lawyer for the preservation group, countered this, saying: "They just don't want to go to Congress."
(c) Sky News 2026: US appeals court blocks Donald Trump's $400m White House ballroom
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