Diplomats say Southeast Asian nations are not able to agree on setting up a human rights commission, and on sanctions against members who fail to obey their regional bloc's rules.
Negotiators meeting in the Philippines are rushing to complete a draft of the Association of Southeast Asian Nation's first charter before foreign ministers from the 10-nation group meet Sunday.
The bloc has agreed on most of the charter, which will help to turn the group into a rules-based organization along the lines of the European Union.
A key sticking point is Burma, which has long been a problem for ASEAN, because of the country's poor human rights record and its detention of activists, including Nobel Peace Prize laureate Aung San Suu Kyi.
Until now, ASEAN has operated without a constitution, choosing to rely on informal diplomacy and decision-making by consensus.
Some information for this report was provided by AFP, AP and Reuters.