WASHINGTON — The Supreme Court on Friday at least for now allowed President Donald Trump to continue constructing a new ballroom adjoining the White House.Chief Justice John Roberts issued a temporary stay that blocks lower court rulings that would have put the above-ground portion of the project on hold.But the decision is only provisional, giving the justices more time to consider next steps.The legal challenge has been brought by the National Trust for Historic Preservation, which argued that the president did not have authority to proceed with construction and objected to the huge new ballroom design on aesthetic grounds.In court filings, the administration has said that as of Aug. 14, construction was 65% complete on the $400 million, privately funded project, with a 250-person crew working 20 hours a day, seven days a week.The plan includes an extensive underground component, including secure locations and medical facilities that the administration has argued are vital for security. A federal judge had ruled in favor of the trust, saying that while the underground construction could move forward, the ballroom itself could not be built while litigation continued.On Aug. 7, the U.S. Court of Appeals for the District of Columbia Circuit upheld that decision, setting the deadline of Friday for construction to halt unless the Supreme Court intervened.