Halting $400m White House ballroom project is national security risk, Trump officials say

US National Park Service lawyers cite materials that will be installed to make ‘heavily fortified’ facility

Donald Trump’s administration is arguing that a judge’s order to halt construction of a $400m White House ballroom creates a security risk for the US president as his team asks a federal appeals court to pause the ruling.

In a motion filed on Friday, US National Park Service (NPS) lawyers say that the federal judge’s order to suspend construction of the new facility is “threatening grave national-security harms to the White House, the president and his family, and the president’s staff”.