UPDATE 1-About 100 U.S. citizens, permanent residents still waiting to leave Afghanistan -official

(Adds details, background)

WASHINGTON, Sept 27 (Reuters) - The United States is aware of about 100 American citizens and legal permanent residents (LPRs) who remain in Afghanistan and are ready to leave the country, a senior State Department official said on Monday.

The State Department was working to get those people on flights out of Afghanistan, said the official, who briefed reporters on condition of anonymity.

"Our highest priority in Afghanistan, of course, remains helping those American citizens who wish to leave the country now to do so," the official said.

About 124,000 people were airlifted out of Kabul after the U.S.-backed government there collapsed last month and the Taliban took control.

Since U.S. forces departed and handed over the airport on Aug. 31, 85 American citizens and 79 LPRs have left Afghanistan on sporadic flights, according to the official.

However, some American citizens did not want to leave Afghanistan without family members who did not have the required travel documents to enter the United States, the official said.

The United States would soon intensify efforts to help the immediate family members of American citizens who did not have the needed documentation, the official said, but would not do so for their “extended" families, which could include a large number of people.

“I entirely understand how painful that choice may be for them, but for matters of law and policy, up to this point, we have not extended support for expedited departure and resettlement in the U.S. for extended family members of U.S. citizens,” the official said. (Reporting by Simon Lewis, Humeyra Pamuk and Jonathan Landay; Editing by Bernadette Baum)