WASHINGTON — A top government official overseeing federal buildings – including the historic tower that is home to President Donald Trump’s D.C. hotel – is leaving the agency as it endures increasing criticism from congressional Democrats for not addressing a potential lease violation and other concerns stemming from the president’s ownership of the project.

Some members of Congress worry that Trump could appoint new leaders who will renegotiate the terms of the lease to eliminate any legal entanglements.

Norman Dong, head of public buildings at the General Services Administration since 2014, is leaving the government in the coming weeks, agency officials and his new employers confirmed Tuesday.

In a draft email to colleagues and staff obtained by The Washington Post, Dong said it had been “an honor and a privilege” to work there. “I am so proud of what we have accomplished as a team,” he said.

Dong’s responsibilities include overseeing publicly leased and owned buildings, including the Old Post Office Pavilion in downtown D.C., where Trump opened a $212 million luxury hotel last fall on a 60-year lease with the agency.

Dong, a civil servant (rather than a political appointee), arrived at the agency after Trump’s deal was made but oversaw the Trump Organization’s completion of the project and was among the agency officials evaluating Trump’s continued ownership of the hotel operation after the business mogul won the election and became president.

Reached by email, Dong directed questions about his departure to a GSA spokeswoman, who declined to comment.

Democrats on Capitol Hill continued to press the agency to address concerns raised by Trump’s profiting from the lease deal, with the latest broadside coming Tuesday from two top members of the subcommittee overseeing the agency.

Reps. Peter DeFazio, D-Ore., and Hank Johnson, D-Ga., wrote to the agency’s inspector general, Carol Ochoa, asking her to “express serious concerns” about the agency’s handling of the Trump lease. A clause in the lease bars an elected official from receiving any benefit from the agreement, and ethics officials have raised concerns about Trump’s continued profiting from business involving foreign governments and political groups at the hotel.

The congressmen raised specific concerns about how taxpayers would be fairly represented in any future lease negotiations with Trump’s children running the company after Trump named his own appointee to run GSA, who would have the authority to modify the lease terms. The 200-page lease has been amended five times.

“Left unchecked, this arrangement is fraught with the possibility that President Trump and his children will enrich themselves at taxpayers’ expense,” they wrote. “This is simply untenable.”

DeFazio and Johnson urged Ochoa, whose office is independent of the agency, to “investigate and report on GSA’s management and administration of the [Old Post Office] lease agreement since President Trump’s election, including identifying any breach of the lease agreement or associated conflicts of interest.”

“For the first time in U.S. history, a sitting President operates and profits from a private business in a taxpayer-owned federal building,” they wrote. Among the questions they asked is whether agency officials have calculated what the cost would be of terminating the Trump Organization’s lease.

Sarah Breen, a spokeswoman for Ochoa, said that the letter had been received. “We are continuing to actively monitor developments in GSA’s management of the Old Post Office lease,” she said.

Trump has taken steps to insulate himself from the business he founded and led, resigning from his positions and putting his adult sons, Donald Trump Jr. and Eric Trump, in charge. He pledged to donate profits from foreign clients to the U.S. Treasury.

But critics say the agency should have acted to address concerns about the lease before the inauguration. On the day Trump entered office, departing GSA Administrator Denise Turner Roth named Dong acting GSA administrator. Later that day, officials in Trump’s new administration replaced Dong with another GSA official, Timothy Horne.

In a brief statement, Roth called Dong “a consummate professional, who was always committed to the mission of the GSA.”

The GSA’s most recent public statement on the hotel lease came Jan. 27, when it said that officials had received information from the Trump Organization and were “reviewing and evaluating this information to assess its compliance with the terms and conditions of the Old Post Office lease.” Roth and Dong declined to discuss the review.

Dong is leaving the government to return to work for his former boss, Anthony A. Williams, for whom Dong was city administrator during Williams’s tenure as D.C. mayor, ending in 2007. Williams is now chief executive and executive director of a private business association, the Federal City Council, that is dedicated to local projects and policies affecting D.C. Dong will be a senior adviser there beginning April 3.