Malaysian Prime Minister Najib Razak has said his country will conduct search and rescue missions for Rohingya migrant boats in the Andaman Sea.
Humanitarian aid would also be delivered by land and sea, he said.
His announcement comes after weeks of authorities rejecting migrant boats and towing them out of Malaysian waters.
Malaysia and Indonesia's foreign ministers are in Myanmar for talks on the migrant crisis. About 7,000 people are believed to be stranded at sea.
Most of the migrants are Rohingya Muslims fleeing persecution in Myanmar, but some are Bangladeshis thought to be economic migrants.
Malaysia and Indonesia have said they will temporarily shelter those that land on their territory, but need the international community's help with resettling them. Thailand says it will no longer push back boat people from its territorial waters.
Mr Najib said on his Twitter account that it was "basic human compassion" to provide aid to the hungry and sick. He added that search and rescue by the country's naval and maritime authorities was needed to "prevent loss of life".
Malaysia was among several states in the region that had previously refused to take in the migrants and been towing the boats to other countries' waters, in what observers condemned as a deadly "ping-pong" match.
Malaysia's foreign minister Anifah Aman and Indonesia's Retno Marsudi are holding talks with Myanmar counterpart U Wunna Maung Lwin in the Burmese capital Nay Pyi Taw. The US deputy secretary of state Antony Blinken is also due to meet Burmese officials.
Thursday's meeting is seen by some as a breakthrough, as Myanmar has denied responsibility for the crisis and did not attend a meeting of regional foreign ministers on Wednesday, where the deal to provide temporary shelter and no longer turn back boats was reached.
"We are not ignoring the migrant problem, but... we will not accept the allegations by some that Myanmar is the source of the problem," Zaw Htay, director of Myanmar's presidential office, told AP news agency on Saturday.
Ship of survivors
Amnesty International's Asia Pacific Director Richard Bennett said Wednesday's decision to provide shelter helped those who have come ashore, but "does nothing for the thousands still adrift at sea, with diminishing supplies of food and water, or for any more who may follow them".
Thailand has said it will stop towing boats back to sea, something Malaysian and Indonesian navies have also been doing in recent days, but did not sign the agreement to provide shelter, saying it is already struggling to cope with tens of thousands of refugees from Myanmar.
Regional media see 'no simple answer'
"If we try to please these people [migrants] out of compassion, we might perhaps satisfy them in the near time, but over time this will create more havoc to the country," says an opinion piece on the Malay Mail newspaper website.
Rights activist Marina Mahathir disagrees.
"The Rohingya problem is not going to go away just because we refuse to help them. Saying that they will keep coming if we feed and shelter them is being simplistic," she writes in the Malaysian tabloid The Star.
Most agree, however, that there is no simple solution to the crisis.
"The Rohingya refugee problem, just like the European boat people crisis, is complex and cannot be easily solved by pointing fingers of blame. There is no simple answer, no single quick-fix," suggests the Thai newspaper The Nation.
More than 3,000 have been rescued by locals or come ashore in Indonesia and Malaysia in recent days.
Malaysia and Indonesia have appealed for help from other nations to resettle the migrants within a year.
- The US has said it is prepared to take in refugees and lead a multi-country effort to resettle them as part of negotiations.
- Gambia also offered to give them refuge, saying it was a "sacred duty" to help fellow Muslims.
- Australia has said it will not accept any of the refugees because it would encourage more people to leave. Prime Minister Tony Abbott has said those seeking asylum should use the "front door" or official channels.
Myanmar (also known as Burma) sees the Rohingya as migrants from Bangladesh, though many generations have lived there. It restricts their movements and personal lives, and Rohingya have faced persecution from the majority Buddhist population.
The BBC's Jonah Fisher, who is in Sittwe province where many of the migrants are believed to have come from, says unless the root cause is addressed the migration problem will continue.
Why has this crisis erupted?
- Rohingya Muslims mainly live in Myanmar, where they have faced decades of persecution.
- Rights groups say migrants feel they have "no choice" but to leave, paying people smugglers to help them. The UN estimates more than 120,000 Rohingyas have fled in the past three years.
- Traffickers usually take the migrants by sea to Thailand then overland to Malaysia.
- But Thailand recently began cracking down on the migrant routes, meaning traffickers are using sea routes instead.