Construction of a project costing about $400 million - equivalent to about 3.8 billion Swedish kronor - is halted until Congress approves the plan, Judge Richard Leon in Washington has ruled.
A preservation group for historic buildings has taken the case to court, demanding that the project undergo several independent reviews and be submitted for approval by Congress.
The White House announced the plans last summer. In late October, Trump had the East Wing of the White House demolished to make way for an 8,400-square-foot ballroom, without consulting the usual authorities for such projects.
