(Adds U.S. request to use Thai airspace, paragraphs 9-10)
By Amy Sawitta Lefevre and Simon Webb
BANGKOK, May 28 (Reuters) - A meeting in Bangkok on Friday about Southeast Asia's migrant crisis is unlikely to produce a binding agreement or plan of action to save thousands of people believed stranded on boats in the Bay of Bengal and Andaman Sea, participants said.
The meeting will bring together 17 countries from across the Association of Southeast Asian Nations (ASEAN) and elsewhere in Asia, along with the United States, Switzerland and international organizations like UNHCR, the U.N. refugee agency.
But many attendees are not ministerial-level and the meeting may not have the heft that organizers in Bangkok hope for. According to the Thai Foreign Ministry, at least three of the countries central to the crisis will not be sending ministers: Myanmar, Indonesia and Malaysia.
Myanmar said on Thursday it had no plans to reach an agreement in Bangkok.
"We are going there only to discuss the regional crisis which all of the ASEAN countries are facing," its delegation head, Foreign Ministry Director-General Htein Lin, told Reuters.
A U.S. statement said the United States would contribute to an emergency appeal by the International Organization for Migration to support a "regionally led" response aimed at ensuring the safety and humane treatment of migrants and an end to discriminatory treatment in Myanmar.
It said Washington would continue to consider resettlement for the most vulnerable refugees as part of any international response led by the U.N. High Commissioner for Refugees.
It said resettlement could not be the primary solution to the crisis, but could be one part of a wider regional effort to address the root causes of migration.
The U.S. statement said the U.S. Navy was conducting daily maritime surveillance flights from Malaysia to locate boats carrying migrants.
A State Department official said that the United States had requested permission from Thailand to conduct surveillance flights through Thai air space to assist the search for vessels carrying migrants, and was awaiting a response.
"We have been in daily contact with the Thai government regarding our request and continue to discuss options for cooperation," the official said.
Anne Richard, assistant secretary of state for population, refugees, and migration, will lead the U.S. delegation on Friday before traveling on to Malaysia and Indonesia.
THOUSANDS BELIEVED ADRIFT
More than 3,000 migrants from Bangladesh and Myanmar have landed in Indonesia and Malaysia since Thailand launched a crackdown on human trafficking gangs this month. About 2,600 are believed to be still adrift on boats, relief agencies have said.
Many who made it to shore are members of Myanmar's 1.1 million Rohingya Muslim minority who live in apartheid-like conditions in the country's Rakhine state.
A source at one international organization, who declined to be named, said the level of representation of the countries at the head of the crisis was of concern.
"They're the main players," he said. "What can they achieve with that level of representation?"
Volker Turk, UNHCR Assistant High Commissioner for Protection, told Reuters the complex crisis could not be resolved in a day but called the meeting "a good beginning."
Myanmar does not consider the Rohingya citizens, rendering them effectively stateless, while denying it discriminates against them or that they are fleeing persecution.
Almost 140,000 were displaced in deadly clashes with majority Buddhists in Rakhine in 2012. About 100,000 have fled overseas since, according to the Arakan Project, a Rohingya advocacy group.
Turk said resolving the issue of statelessness in Myanmar was vital.
"If that's not currently possible because of the law, making sure they are given an equivalent status, a legal status, is incredibly important to resolving the crisis," he said.
Thai Foreign Ministry spokesman Sek Wannamethee said the meeting was aimed at "commitment to international cooperation to resolve this humanitarian crisis."
"We hope that this meeting will yield similar short- and long-term solutions to the problem. This meeting is aimed at alleviating the suffering of those still at sea," he said. (Additional reporting by Hnin Yadana Zaw in YANGON and David Brunnstrom in Washington; Editing by Raju Gopalakrishnan, Jonathan Oatis and Alan Crosby)