Myanmar has refused to be singled out for blame for the Asia migrant crisis at a conference of the regional grouping Asean in Bangkok.
Delegates said the situation was at an alarming level. Representatives of the US and UN are also at the meeting.
Thousands of people have fled Bangladesh and Myanmar by boat, heading south to Thailand, Indonesia and Malaysia.
The UN estimates about 2,600 migrants are still stranded out at sea.
Most are economic migrants from Bangladesh and Rohingya Muslims fleeing persecution in Myanmar - also known as Burma.
The crisis began earlier this year when Thailand cracked down on overland migrant routes, forcing people smugglers to use sea routes instead.
Myanmar's foreign ministry chief Htin Lynn said his country would co-operate in dealing with human trafficking.
But he also told delegates that on "this issue of illegal migration of boat people, you cannot single out my country.
"Finger-pointing will not serve any purpose. It will take us nowhere."
In his opening remarks, Thai Foreign Minister Tanasak Patimapragorn said "the influx of irregular migrants... has reached alarming levels".
He added that "the root causes that motivated these people to leave must also be addressed", in comments apparently directed at Myanmar and Bangladesh.
US assistant secretary of state Anne Richard also urged swift action to save the lives of migrants out at sea.