From left, Secretary of State John F. Kerry and former secretaries Hillary Clinton, Colin L. Powell and Madeleine Albright attend a reception celebrating the completion of the U.S. Diplomacy Center Pavilion in Washington on Tuesday. (Yuri Gripas/Reuters)

Hillary Clinton made a rare and low-key return to Washington on Tuesday for the ceremonial opening of a new exhibition and museum area at the State Department that will be partly named for her.

Clinton appeared alongside fellow former secretaries of state Madeleine Albright and Colin L. Powell to inaugurate the glass pavilion — yes, there is a glass ceiling — that forms the new public entrance to the building. All living former secretaries of state were invited, but others declined for scheduling reasons, department spokesman John Kirby said Monday.

“I’m sure you will notice it is the most transparent part of the entire project,” Clinton joked about her namesake hall at the U.S. Diplomacy Center.

It was only Clinton’s second public appearance in Washington since losing the Nov. 8 election. Her brief remarks praised diplomats and the work of American diplomacy, and made no mention of the election.

The other halls, holding exhibits, an auditorium and a classroom, will be named for former secretaries James A. Baker and Henry Kissinger, and for current Secretary of State John F. Kerry.

Clinton speaks at the reception at the State Department on Tuesday. One hall at the U.S. Diplomacy Center will be named for her. (Mark Wilson/Getty Images)

Democrats and State Department officials rushed to hold the ceremony in the closing days of the Obama administration, even though the project is not complete. Unofficial plans had called for a grand opening of the entire facility in 2018.

The incoming Trump administration has not said how or whether it plans to finish the center, and some backers have questioned whether a project conceived and built almost entirely by Democratic administrations will be a priority.

Only the Clinton hall and the Kissinger one below it — whose star attraction is a 14-foot section of the Berlin Wall — are complete and ready to open. Estimated at $50 million, which was raised, the public-private project now needs roughly $20 million more to complete and outfit the other halls.

Kerry plugged what he said would be an ongoing fundraising effort.

“In any marathon, the last few miles are always the hardest,” he told the crowd of diplomats, donors and others seated in the new hall. “We still have a few miles to go.”

Earlier Tuesday, Kerry said that contact between current and incoming State Department officials has been limited.

“It’s going pretty smoothly, because there’s not an enormous amount of it,” Kerry joked to an audience at the U.S. Institute of Peace.

“There are some people who have been in the building for a period of time, but quite candidly, I think there has not been a lot of high-level exchange.”

Kerry said he has not yet met Rex Tillerson, Trump’s pick to succeed him as secretary of state, but expects to do so before he leaves office.

The Diplomacy Center, a glass-fronted addition to the hulking State Department building, will house a museum of diplomatic history and artifacts. It is also meant to give a welcoming front door to a forbidding structure otherwise walled off by security gates and concrete barriers.

A State Department website devoted to the project says this section will “engage visitors in exploring U.S. relationships with nations around the world.”

The museum was conceived by Albright, who held a symbolic groundbreaking for it in 2000, near the close of Bill Clinton’s presidency. The project languished during the George W. Bush years and was revived by Hillary Clinton, who deputized longtime donor and friend Elizabeth Frawley Bagley to raise outside money.

The bulk of the $50 million raised so far came in during Clinton’s four-year tenure as President Obama’s first secretary of state, from 2009 to 2013. Clinton was not running for president at the time but was widely presumed to be contemplating a second White House run in 2016.

State Department emails from Clinton’s term, released under court directive as part of the fallout over her private email system, chronicle some of the millions of dollars in corporate, foundation and other donations she helped draw for the project.

Some of the donors overlap with Clinton’s network of political fundraisers and with donors to the Clinton family’s charitable foundation.