Burma's neighbours have been urged to accept refugees who are fleeing abroad to escape bloody communal violence.
The call from refugee organisations is in response to ongoing violence in Burma's Rakhine state between Buddhists and the Muslim Rohingya minority.
Dozens of people have been killed since June and refugee camps have been swamped, with tens of thousands fleeing the bloodshed.
Rohingya have for years trickled abroad to neighouring Bangladesh and, increasingly, to Muslim-majority Malaysia by boat.
The violence has sparked warnings of a potential surge in refugees opting for the dangerous sea voyage.
Bangladeshi police say about 130 people are missing after a boat sank Sunday while carrying Rohingya refugees heading for Malaysia.
"We are appealing to countries to keep borders open and to ensure safe access and whatever assistance they can provide," said Vivian Tan, Asia-Pacific spokeswoman for the United Nations High Commissioner for Refugees.
Rohingyas, a Muslim minority who speak a Bengali dialect in mainly Buddhist Burma, claim decades of persecution.
The government views the roughly 800,000 Rohingya in Rakhine as illegal Bangladeshi immigrants and denies them citizenship.
Decades-old animosity between Buddhists and Rohingya exploded in June after the apparent rape and murder of an ethnic Rakhine woman sparked a series of revenge attacks.