BANGKOK — The United States and South Korea on Sunday said they were postponing a joint military air exercise that North Korea has criticized as provocative.

U.S. Defense Secretary Mark Esper and his South Korean counterpart made the announcement in Bangkok, where they were attending an Asia defense ministers’ conference.

Esper told reporters he did not consider the postponement a concession to North Korea.

“We have made this decision as an act of goodwill to contribute to an environment conducive to diplomacy and the advancement of peace,” Esper said.

As recently as Friday, when Esper was in Seoul to consult with South Korean officials, there was no word on postponing the military air exercise, which had been called Vigilant Ace.

Seoul and Washington had scaled back the exercise recently and changed the name, but North Korea strongly objected, calling it evidence of a lack of interest in improving relations.

The North has demanded accommodations before it will agree to resume nuclear negotiations.

As talks stall, Pyongyang has tested the limits of engagement with a string of missile launches, and experts warn that the lack of a concrete arms control agreement has allowed the country to continue producing nuclear weapons.

The missile tests have practical value for the North Korean military’s efforts to modernize its arsenal. But they also underscore its increasingly belligerent position in the face of what it sees as an inflexible and hostile United States.

South Korean Defense Minister Jeong Kyeong-doo said the exercise had been put off pending further consultations between Seoul and Washington. No new date has been set.

“I see this as a good-faith effort by the United States and the Republic of Korea to enable peace ... to facilitate a political agreement, a deal if you will, that leads to the denuclearization of the Korean Peninsula,” Esper said.

He said Seoul and Washington encourage North Korea “to demonstrate the same goodwill” as it considers decisions on its own military training, exercises and testing.

He also urged the North to return to the negotiating table “without precondition or hesitation.”

Esper said that even without the planned exercise of South Korean and American air forces, both militaries “will remain at a high state of readiness” for potential combat.

The U.S. has about 28,000 troops in South Korea.