VIENTIANE, Laos (Reuters) -Southeast Asian leaders met in Laos on Wednesday for a summit expected to seek ways address the worsening civil war in Myanmar, with Thailand calling for heightened engagement ahead of a planned election by the country's embattled military rulers.

Southeast Asian leaders are meeting at an annual forum that will focus on the civil war in Myanmar and territorial tensions in the South China Sea, two challenges that have long tested the bloc's credibility.

Myanmar’s shadow government, the National Unity Government (NUG), has called for the junta's exclusion from ASEAN meetings and praised the creation of a group of three countries, consisting of Indonesia, which chaired the bloc last year, Laos and Malaysia, to address the crisis.