KABUL, Afghanistan — Afghans who worked for the American military and government are being told that they cannot apply for special visas to the United States, even though Afghanistan is not among the countries listed in President Trump’s new travel ban, according to advocates for Afghan refugees.

As of Thursday, Afghans seeking to apply for what are known as Special Immigrant Visas were being told by the American Embassy in Kabul, the capital, that applications would no longer be accepted, according to Senator Jeanne Shaheen, Democrat of New Hampshire.

Officials at the embassy did not immediately respond to requests for comment. It was unclear if the visa suspension was related to the president’s new ban, which, in addition to denying visas to citizens of six predominantly Muslim countries, also orders that the number of refugees allowed into America be cut by more than half, to 50,000 this year, from 110,000 in 2016.

Ms. Shaheen, along with Senator John McCain, Republican of Arizona, has been a strong advocate of the Special Immigrant Visa program, meant for Afghans who face the threat of reprisal for their work with Americans. Its apparent suspension could affect as many as 10,000 applicants. “Allowing this program to lapse sends the message to our allies in Afghanistan that the United States has abandoned them,” Ms. Shaheen said in a statement.