The closed-door talks on Thursday put US Secretary of Defense Lloyd Austin and Chinese Defence Minister Dong Jun in the same room a day after Dong refused a request to meet with Austin one-on-one on the sidelines of the ASEAN Defence Ministers Meetings.
The US and China have been working to improve frayed military-to-military communications and Austin said he regretted Dong's decision, calling it "a setback for the whole region".
Chinese Defence Minister Dong Jun refused to meet US counterpart Lloyd Austin one-on-one. (AP PHOTO)
The ASEAN meetings come as member nations are looking warily towards the change in American administrations at a time of increasing maritime disputes with China.
The US has firmly pushed a "free and open Indo-Pacific" policy under outgoing President Joe Biden and it is not yet clear how the incoming administration of President-elect Donald Trump will address the South China Sea situation.
As well as the United States and China, other nations attending the ASEAN meeting from outside Southeast Asia include Japan, South Korea, India, Russia, Australia and New Zealand.
The meetings with the ASEAN dialogue partners were also expected address tensions in the Korean Peninsula, the Russia-Ukraine war, and wars in the Middle East.
Before heading to Laos, Austin concluded meetings in Australia with officials there and with Japan's defence minister.
They pledged to support ASEAN and expressed their "serious concern about destabilising actions in the East and South China Seas, including dangerous conduct by the People's Republic of China against Philippines and other coastal state vessels".
Pentagon chief Lloyd Austin called Dong Jun's refusal "a setback for the whole region". (AP PHOTO)
Along with the Philippines, ASEAN members Vietnam, Malaysia and Brunei have competing claims with China in the South China Sea, which Beijing claims almost entirely as its own territory.
Indonesia, Thailand, Singapore, Myanmar, Cambodia and Laos are the other ASEAN members.
As China has grown more assertive in pushing its territorial claims in recent years, it and ASEAN have been negotiating a code of conduct to govern behaviour in the sea, but progress has been slow.
Officials have agreed to try to complete the code by 2026, but talks have been hampered by thorny issues, including disagreements over whether the pact should be binding.
Chinese and Philippine vessels have clashed repeatedly in 2024, and Vietnam in October charged that Chinese forces assaulted its fishermen in disputed areas in the South China Sea.
China has also sent patrol vessels to areas that Indonesia and Malaysia claim as their exclusive economic zones.
Another thorny regional issue is the civil war and humanitarian crisis in ASEAN member Myanmar.
The group's credibility has been severely tested by the war in Myanmar, where the army ousted an elected government in 2021, and fighting has continued with pro-democracy guerrillas and ethnic rebels.
More than a year into an offensive initiated by three militias and joined by other resistance groups, observers estimate the military controls less than half the country.
Myanmar military rulers have been barred from ASEAN meetings since late 2021, but in 2024 the country has been represented by high-level bureaucrats.
Meetings on Wednesday also discussed military co-operation, transnational haze, disinformation, border security and transnational crimes such as drugs, cyber scams and human trafficking,
