Several Southeast Asian air force commanders will shun an upcoming meeting chaired by Myanmar's military rulers, officials told AFP, deepening the junta's regional isolation as it struggles to crush resistance.

The annual ASEAN Air Chiefs Conference gathers top air force leaders from the 10-nation bloc to discuss cooperation in defence, combating extremism and disaster relief.

Current chair Myanmar is set to host the meeting next week but at least three Association of Southeast Asian Nations (ASEAN) countries told AFP they will not send their top officials.

The junta has been accused of war crimes over air strikes carried out by its jets — mostly Chinese and Russian-built — in support of ground troops battling opponents of its 2021 coup.

Its air force chief Htun Aung, who will chair the conference, has been sanctioned by the United States and Britain.

The air force chiefs of the Philippines, Malaysia and Indonesia will not attend the meeting, officials told AFP.

Malaysia's air force chief will not attend, a spokesperson said, while the Philippine commander will send a video message to his counterpart rather than go in person.

Indonesia's air force chief "will not be attending and won't be sending anyone to represent him either", air force spokesperson Agung Sasongkojati told AFP without giving a reason.

At a summit this week, ASEAN accused the junta of targeting civilians in the grinding conflict sparked by its coup, and of ignoring a peace plan agreed with the bloc to end violence.

Indonesian Foreign Minister Retno Marsudi said there had been "no significant progress" in the five-point plan agreed with the junta more than two years ago.

The junta slammed that assessment as "one-sided".

ASEAN has barred junta officials from high-level meetings over their refusal to engage with the plan and their opponents.