WASHINGTON — The stampede of diners who once rushed through the State Department’s vast cafeteria has ebbed, with diplomats who previously grabbed quick bites between meetings now lingering over Korean barbecue and checking their phones for some kind of news.

Many have little to do until the Trump administration starts filling the nearly 200 jobs at the department that require Senate confirmation, and their agendas look increasingly as though they will remain empty. Secretary of State Rex W. Tillerson has done almost nothing to select leaders for the White House’s consideration, and nominations for assistant secretaries and others who largely run the State Department are unlikely to be made for months.

In an unusual interview, R. C. Hammond, Mr. Tillerson’s spokesman, said the secretary intended to embark within days on a listening tour of the building and then a restructuring of the department’s operations. Only after those are underway will he begin to name his wider leadership team.

With a Senate confirmation process that takes months, that means the department will remain largely leaderless until well into 2018. And no other department in the federal government is as dependent on political appointees, or as paralyzed when the appointment process freezes.