“These are unprecedented circumstances,” the State Department said in an emailed statement. “We recognize the closing of borders and air space, lack of flights, and other local conditions make travel difficult and it may not be advisable to immediately repatriate all exchange participants.”

In a statement, the University of North Carolina said its officials were in “regular communication” with the students in Guatemala and were “working diligently on arrangements for their safe return home.”

Several American students said they had received limited information from U.S. embassies over the past week, as governments around the world instituted emergency measures to contain the spread of the coronavirus, including the sealing of borders.

“For me, it was really disheartening to see the embassy, the State Department, wasn’t able to help us,” said Ms. Stirrat, 20, a junior at Lewis & Clark who eventually got on the Boston University-chartered evacuation flight from Ecuador. “It kind of makes me think twice about what it means to be American and how much the government cares for its citizens.”

Ms. Stirrat, her fellow student Kasia Enriquez, and their faculty adviser, Stephen Tufte, had been trying to get out of Ecuador for nearly a week after the country blocked all incoming flights, which effectively shut down outgoing flights, too.

The dearth of commercial flights has left students and their advisers with, at best, a patchwork of options. Mr. Neria, 21, the Arabic-language student from Lewis & Clark, was allowed to board a British government-sponsored evacuation flight from Morocco.

In Peru, Jessica Buie, 25, a student at Lenoir-Rhyne University in North Carolina, said she and her fellow students packed their bags and headed to the U.S. Consulate in Cusco as soon as they got word that the Peruvian government would close its border.