Just over 1,400 visas are left in a special program for Afghans who worked for the U.S. government in Afghanistan, less than a tenth of what is needed for all the Afghans who have applied for such visas, a State Department official said on Friday.

U.S. military forces have been engaged in Afghanistan for a decade and a half, and often rely on Afghans to serve as interpreters or provide other crucial support. Those individuals face serious threats by the Taliban insurgency for their work, and the Special Immigrant Visa program allows them to resettle in the United States.

The State Department said in an online bulletin on Thursday that it had halted interviews for Afghans applying for the visas because it anticipated exhausting the visas, whose numbers are allocated by Congress, by the middle of this year.

Of 8,500 special immigrant visas authorized by Congress for Afghan applicants, just 1,437 remained as of March 5, a State Department official said on Friday on condition of anonymity.

"There are more than 15,000 Afghan principal applicants at some stage of the SIV application process," the official said. "We do not expect to resume scheduling appointments unless new SIV numbers are allocated by Congress."