BANGKOK, Dec 3 – Southeast Asia needs legal channels of migration to help curb human smuggling, the International Organization of Migration said on Thursday, days after it urged efforts to avoid a repeat of this year's disaster when hundreds of refugees were lost at sea or died in jungle camps.

The 10-member Association of Southeast Asian Nations established an economic community last month to free up capital and trade, but made limited provision for labour movement even though the region has millions of migrant workers.

"There needs to be more legal channels of migration, so that we don't end up unintentionally subsidizing the smugglers," IOM Director General William Lacy Swing told reporters.

"If the visa regime makes it impossible for people to get to the jobs that are there to be filled, then obviously they will go to smugglers and pay a lot of money."

Thousands of migrants from Bangladesh and Myanmar have fled persecution and poverty in recent years, putting their lives in the hands of human smugglers to reach countries with better prospects in Southeast Asia and beyond.

Lacy spoke ahead of a meeting in Bangkok this week to address the migrant crisis, a follow-up to a meeting that took place in May as the humanitarian disaster unfolded, just as European countries were struggling to cope with refugees fleeing war in Syria and Iraq.

A clamp-down by Thai police on human trafficking gangs triggered the regional crisis earlier this year. It followed the discovery in May of 30 bodies in graves near the Thai-Malaysian border, which sparked international outcry.

The crackdown disrupted smuggling routes, leaving thousands of migrants abandoned at sea. More than 4,000 of them landed in Indonesia, Malaysia, Thailand, Myanmar and Bangladesh.

More than 1,900 migrants from Myanmar and Bangladesh are still in shelters and immigration detention centres, according to the IOM. Many of them are members of Myanmar's Rohingya Muslim minority who fled apartheid-like conditions in the country's Rakhine state.

It was as yet unclear if a November election in Myanmar won by the Aung San Suu Kyi's opposition National League for Democracy would lead to an improvement in the situation of the Rohingya, Lacy said.

October and November mark the start of the four-month "sailing season", the busiest time for smuggling and trafficking ships plying the Bay of Bengal.