About 18,000 Afghans who have applied for the U.S.’s Special Immigrant Visa, as well as their families, remain on the ground in Afghanistan, with about half of those outside Kabul, in areas either already under Taliban control or likely to fall soon, a congressional aide said.

In addition, the State Department this month said tens of thousands more Afghans would be eligible for priority treatment under a U.S. refugee settlement program. The new criteria applied to Afghans who worked for U.S. government contractors, U.S.-funded programs and U.S.-based media or nongovernmental organizations, as well as their families.

The precise criteria remain uncertain, and the State Department hasn’t said whether part-time and contract workers for U.S. organizations would be eligible. The prospective refugees would have to get themselves out of Afghanistan to a third country at their own expense, the State Department said.

Former soldiers, aid workers and others who previously worked in Afghanistan have been inundated with requests from former Afghan colleagues and employees seeking letters of recommendation and help in fleeing the country.