The top U.S. officer in Afghanistan talks with the Taliban almost every day.

On the ground in Kabul, Rear Adm. Peter G. Vasely, a former member of the Navy SEALs who is now the top U.S. military officer in Afghanistan, talks daily or near daily with his Taliban counterparts regarding security measures at the airport, Pentagon officials said on Monday.

As the Pentagon rushes to evacuate tens of thousands of people before President Biden’s Aug. 31 deadline for withdrawing troops from Afghanistan, the discussions between Admiral Vasely and Taliban commanders have helped set the rules of engagement to allow Americans and some Afghan allies to reach Kabul’s airport. At the same time, the U.S. has been sending helicopters and troops beyond the airport to extract people who can’t get there on their own.

Other American officers down the military chain of command in Kabul have also engaged with Taliban commanders on specific security and threat reduction issues, the officials said — a partnership of necessity between parties that spent 20 years on opposite sides of a war.

The regular discussions between American and Taliban commanders yielded an agreement in which Taliban fighters expanded the security perimeter outside the airport, pushing back the massive crowds of Afghans and others seeking access to flights out.

Gen. Kenneth F. McKenzie Jr., the head of the military’s Central Command, first spoke to senior Taliban commanders on Aug. 15 when he was in Doha, Qatar, to help get the evacuation effort off the ground.

Al Udeid Air Base, a sprawling airfield outside Doha, has become the main receiving station for thousands of Afghans arriving on American military flights from Kabul.