Burma's neighbours have expressed doubts over the country's new draft constitution, implicitly criticising the Burmese government.
Critics say the constitution will strengthen the government's power
Speaking on behalf of Asean, Singapore Foreign Minister George Yeo said there were concerns over the credibility of the new text and forthcoming polls.
It would ultimately be up to the Burmese people to vote "yes" or "no" in a referendum later this year, he added.
The US has also criticised the text and cast doubts over the poll's fairness.
Mr Yeo was speaking as the host of a meeting of the regional body, Asean (Association of South East Asian Nations), in Singapore.
"What we are concerned about is the credibility of the process," Mr Yeo said.
"There must be provisions for independent verification and many of us expressed the view that Myanmar [Burma] cannot ignore the international dimension," he added.
"This is something that they have to decide on their own. In the end, it's for the Myanmar people to vote 'yes' or 'no' to it in the referendum."
He earlier said some ministers at the meeting found it odd that the Burmese constitutional draft barred the pro-democracy leader, Aung San Suu Kyi, from standing for election.
Separately, the US said preventing Ms Suu Kyi from running in the elections casts doubts on the vote.
"That is hardly the definition of free and fair elections. The junta needs to start from scratch with a real draft constitution that actually passes the laugh test," White House national security spokesman Gordon Johndroe said.
Burma's military government announced on Tuesday that a draft of the nation's new constitution had been completed.
The document was drafted behind closed doors by an army-appointed body, and little is known of its contents.
The draft will be put to a referendum in May, and be followed by elections in 2010, according to state media.
The constitution bars Ms Suu Kyi from standing as a candidate because she had a foreign husband.
Ms Suu Kyi's party said it was "unjust" to ban her from standing before the draft was even approved.
The country has not had a constitution since the military seized power in 1990, after refusing to recognise Ms Suu Kyi's victory in a national election.
The pro-democracy leader has spent most of the years since then in jail or under house arrest.