BANGKOK — The Association of Southeast Asian Nations faces a showdown over whether to reverse its five-year ban on Myanmar's military leaders from high-level meetings, a test of the bloc's unity ahead of its upcoming summit.

Thailand has emerged as the junta's most vocal advocate. Bangkok's foreign ministry hosted Myanmar's foreign minister, Than Swe, for informal talks in July—a move that drew sharp criticism from Indonesia, Malaysia, and the Philippines, as well as human rights organizations. Laos and Cambodia have also increased engagement with Naypyidaw, arguing the ban has failed and instead isolated the regime while hindering humanitarian access.

The military seized power in a 2021 coup and was barred from top-tier ASEAN gatherings after a violent crackdown on dissent. Since then, Myanmar has descended into civil war, with widespread displacement and humanitarian crisis that complicates any effort to re-engage the regime.

Indonesia, Malaysia, and the Philippines argue that lifting the ban would legitimize the junta and abandon Myanmar's democratic opposition. A senior Indonesian diplomat, speaking on background, said easing restrictions would betray the democratic aspirations of the Myanmar populace. The bloc's special envoy has made little progress in facilitating dialogue or securing aid access.

The divide exposes competing interests within ASEAN. Thailand shares a long, porous border with Myanmar and has significant trade interests, making stability a primary concern for Bangkok. Lifting the ban would grant the junta international recognition, potentially strengthening its grip on power while weakening the opposition National Unity Government and ethnic armed groups.

The bloc's foundational principle of non-interference clashes with its stated commitment to human rights and governance standards. A decision is expected during the closed-door leaders' retreat scheduled for the summit's final day.