According to the terms under discussion, the body would take a "constructive and non-confrontational approach" to promote and protect human rights, and not investigate or prosecute human rights violators.
Kasit Piromya, the Thai foreign minister said that Asean ministers were "generally in support" of the rules guiding the Asean Intergovernmental Commission on Human Rights.
"The draft of the terms of reference reflects a consensus among Asean countries ... and it is important to make this human rights body credible, but at the same time take into account the real situation in Asean member countries," Kasit told reporters on Sunday.
Kasit also said that "compromises" will have to be made to ensure that Myanmar signs on.
The country continues to provoke international condemnation over its human rights record, as well as the detention of pro-democracy leader Aung San Suu Kyi, who is on trial after allegedly violating the terms of her house arrest.
She faces up to five years in jail if convicted.
Asked whether the Asean rights body would have any way of enforcing human rights in Myanmar, Kasit said that under the likely terms the watchdog would "seek information from member countries" on their internal rights issues.
But he said Myanmar had not disagreed with any of the terms of reference in the foreign ministers' meeting on Sunday.
"It has been part and parcel of the whole drawing up of the terms of reference and the foreign minister of Myanmar was here with us and agreed on the draft terms of reference," Kasit said.
| Myanmar's poor human rights record has been a challenge for Asean [EPA]
A draft of the terms of reference also affirms Asean's underlying principle of non-interference in the domestic affairs of its member, which has been used by some members to fend off criticism about alleged rights abuses.
It lists no sanctions for countries that fail to provide the required reports on their human rights situation and it rejects notions of a universal standard of human rights.
The endorsement of human rights has been a challenge for Asean in the 42 years since it was founded to counter against the spread of communism.
Its members now include an absolute monarchy, a dictatorship and two communist states.
Myanmar has been Asean's so-called "problem child" since it was admitted to the bloc in 1997, with the group under pressure from the US and EU to take a tougher line on Myanmar's military rulers.