Asean leaders are expected to approve the declaration in a major summit in November.
The feeling from ASEAN officials was that Burma, should be rewarded.
Regional tensions have risen recently, with Vietnam and the Philippines accusing China of aggressive behavior in the sea.
A code of conduct would help Vietnam and the Philippines, which are both members of Asean.
The meetings come amid rising tensions between ASEAN members and China over the South China Sea.
US Secretary of State Hillary Clinton’s trip to the Asean Regional Forum in Phnom Penh next week will mark her second visit to Cambodia.
Tribunal spokesman Lars Olsen told the gathering that there would be no more new cases beyond those already before the court.
Interpol equipment linked to the database has been installed in Cambodia since June, officials said.
Secretary of State Hillary Clinton is scheduled to attend an Asean security forum this month.
The symposium, called “Learning from the Past: Global Perspectives on Holocaust Education,” ends Monday.
Recent statistics show Internet penetration in Cambodia at only about 3 percent, but growing.
The contentious issue of the South China Sea will also likely be on Clinton’s agenda, as she moves to further engagement in the region.