Myanmar has been in turmoil since the military putsch that ousted Aung San Suu Kyi's government in February 2021, with the junta's bloody crackdown on dissent sparking social unrest and an economic disaster.

ASEAN, long decried by critics as a toothless talking shop, has been trying to kick-start a five-point plan agreed with Myanmar two years ago after mediation attempts to end violence failed.

But its efforts have stalled as the junta ignores international criticism and refuses to engage with its opponents, which include ousted lawmakers, anti-coup "People's Defense Forces" and ethnic minority armed groups.

An air strike on a village in a rebel stronghold last month that reportedly killed dozens of people sparked global condemnation and worsened the junta's isolation.

Diplomats told AFP that the crisis would be a key issue during the May 9-11 summit in Labuan Baju, East Nusa Tenggara, as Indonesia is this year’s chair of ASEAN.  

The 10-member regional bloc will again "strongly condemn" the air strike and demand an immediate end to the violence in its end-of-summit statement to be issued by Indonesia, according to a draft seen by AFP.

"This would be the only way to create a conducive environment for an inclusive national dialogue to find a sustainable peaceful solution in Myanmar," the draft statement said.

Myanmar remains an ASEAN member but has been barred from top-level summits over the junta's failure to implement the peace plan. 

'Quiet diplomacy'

Indonesian Foreign Minister Retno LP Marsudi said Friday that the government was using "quiet diplomacy" to speak with all sides of the Myanmar conflict and spur renewed peace efforts.

But former foreign minister Marty Natalegawa said the worsening crisis posed an "existential threat" to ASEAN. 

He urged the bloc to do more or risk being sidelined as other nations, such as China and individual member countries of ASEAN, take the lead in trying to resolve the situation.

Natalegawa said ASEAN should "openly invite" the National Unity Government (NUG), a shadow administration dominated by lawmakers from Suu Kyi's party which is working to overturn the coup, to their meetings to make the junta "feel the consequence of their intransigence".

"We are led to believe that there is some quiet diplomacy going on, but it can't be too quiet that it becomes a deafening silence," Natalegawa told AFP.

But Singapore Foreign Minister Vivian Balakrishnan has urged caution and "strategic patience".

"We need to make sure the actions we take collectively and individually do not make the situation worse and do not allow or encourage or enable the military to shed more blood for their own narrow parochial interests," Balakrishnan said in Australia last week.

This week's ASEAN leaders summit is the first of two to be held in Indonesia this year.

Jakarta's chairmanship of the bloc has raised hopes ASEAN could push for a peaceful solution, using its economic weight as well as its diplomatic experience.

ASEAN has long been criticized for its inaction but its initiatives are limited by its charter principles of consensus and non-interference.

Among other issues to be discussed at the summit will be the disputed South China Sea. Several ASEAN members have partial claims to the waterway, which China claims almost entirely.

President Joko “Jokowi” Widodo is also expected to outline a roadmap for Timor-Leste's membership in the bloc.