WASHINGTON — President Donald Trump’s plans to build a skyline-altering arch in the nation’s capital is getting another review from the federal commission whose approval he needs, but the agency’s staff says the project should be revised before it gets the go-ahead.

The National Capital Planning Commission is meeting Thursday, and the Republican president’s proposed 250-foot (76-meter) arch is one of the items on the agenda.

In a report, the agency’s staff recommends that the commission approve the preliminary site and building plans for the arch. But the staff also recommends that the design be tweaked to comply with a federal law that limits building heights in downtown Washington to preserve the city’s famous skyline. The planning commission applies the law during its approval process.

“Staff suggests the Commission request the applicant revise the project design to comply with the Height of Buildings Act and return to NCPC for final approval,” the 185-page report says.

Applying the law “would require design revisions to redistribute the height between the main structure, habitable roof structure and statuary,” the report said. But even with the recommended revisions, the arch, a public observation deck and three gilded topper statues would still reach Trump’s desired 250-foot height, the report said.

The staff is also recommending that commissioners seek additional information about vehicular traffic around the arch, the proposed granite exterior and other aspects of the project before the Interior Department, which oversees the park service, returns for final approval. Trump wants to build the arch on a traffic circle on the Virginia side of the Memorial Bridge from the District of Columbia.

The U.S. Commission of Fine Arts, a separate federal agency, approved the design for the arch in May. The National Capital Planning Commission oversees construction on federal land in the city and began reviewing the arch plan in June.

Opponents of the project argue that the arch is too big for the skyline and would disrupt carefully designed views between the Lincoln Memorial and Arlington National Cemetery that were meant to symbolize the reunification of the North and the South after the Civil War.

But the opposition has done little to influence the members of either commission, both of which include some of Trump’s closest allies. Trump appointed Will Scharf, a top White House aide, to lead the planning commission.

A group of veterans and a historian have sued the Trump administration in federal court to block the arch construction over concerns about disruptions to the sightline.

The arch would be more than twice as tall as the Lincoln Memorial, which is 99 feet (30 meters) tall, and close to half the height of the Washington Monument, at about 555 feet (169 meters) tall.

Trump had said last year that the arch could be paid for with unused funds from the hundreds of millions of dollars he said he has raised from corporations, donors and other wealthy people to pay to build a new $400 million ballroom at the White House.

But, as it turns out, some public money will be used for the ballroom project, as well as the arch. The White House has not released a cost estimate for the arch.