Malaysian naval vessels searched for migrants stranded at sea on Friday as the U.S. prepared to help Southeast Asian countries address the plight of the Rohingya.

The Malaysian operation is the first official rescue effort since the humanitarian crisis erupted earlier this month. Malaysia's Navy chief Abdul Aziz Jaafar said three helicopters and three other ships were on standby to search the country's territorial waters for the boats loaded with Rohingya fleeing Myanmar.

Senior Myanmar General Min Aung Hlaing “hinted that most victims are expected to assume themselves to be Rohingya from Myanmar in the hope of receiving assistance from UNHCR” during a meeting with U.S. Deputy Secretary of State Antony Blinken on Thursday, the government-backed Global New Light of Myanmar newspaper reported.

“He stressed the need to investigate their country of origin rather than to accuse a country,” the newspaper reported.

Myanmar does not consider Rohingya people citizens, and in February, President Thein Sein's government rescinded a 2010 law that extended voting rights to the country's 1 million Rohingya after intense pressure from far-right Buddhist groups.

Washington has been urging governments in the region to work together to conduct search and rescue and provide shelter to thousands of vulnerable migrants.

Pentagon spokesman Lt. Col. Jeffrey Pool said Thursday that the Department of Defense “is responding to this crisis and taking this seriously. We are preparing to stand up maritime aviation patrols throughout the region and [work] with local partners to help with this issue.”

It was the first indication that the U.S. military is ready to take direct role. Washington has been urging governments in the region to work together to conduct search and rescue and provide shelter to thousands of vulnerable migrants.

More than 400 Rohingya and Bangladeshis were brought ashore in the Indonesian province of Aceh on Wednesday, the latest in a series of arrivals bringing hundreds of migrants and refugees — many of whom had spent months at sea.

The new arrivals were in “very, very bad shape,” Joe Lowry, spokesman for the International Organization for Migration, said Thursday, adding that the migrants were in a worse state than their rescuers had expected. Although no one was rushed to the hospital and there were no deaths, the migrants were very sick, dehydrated, malnourished and traumatized, Lowry said.

A bipartisan group of 23 U.S. lawmakers had urged the Obama administration on Wednesday to prevent Southeast Asian seas from becoming a “graveyard” for thousands of Rohingya people.

The lawmakers made the appeal in a letter to U.S. Secretary of State John Kerry late Wednesday, ahead of discussions on the crisis between Myanmar's government and a top U.S. diplomat, Anthony Blinken, in Naypyidaw, Myanmar's capital which took place on Thursday.

The members of the House of Representatives said the U.S. should provide support in search and rescue and humanitarian assistance for migrants in imminent danger in the Andaman Sea after fleeing “systematic repression” in Myanmar.

The U.S. should also work with Southeast Asian nations and address the “root cause” of the crisis, it said.

Buddhist extremist groups have targeted the Rohingya in violent attacks in Myanmar, killing hundreds and displacing over 100,000 members of the ethnic minority and other Muslims.

More than 3,000 people have landed in Indonesia, Malaysia and Thailand in recent weeks, most of them members of the Rohingya minority who were fleeing Myanmar or were tricked by traffickers and then abandoned at sea.

State Department officials in Washington said earlier that the U.S. was willing to lead multi-country efforts organized by the U.N. refugee agency to resettle the most vulnerable migrants. The U.S. has resettled more than 1,000 Rohingya since last October, State Department spokeswoman Marie Harf said earlier.

Meanwhile, Australian Prime Minister Tony Abbott — who has received international criticism for his government’s controversial migrant policies — had said the country would not be resettling any Rohingya refugees.

“Nope, nope, nope,” Abbott told reporters Thursday when asked about resettlement in Australia. “We are not going to do anything that will encourage people to get on boats. If we do the slightest thing to encourage people to get on the boats, this problem will get worse, not better.”

Malaysia and Indonesia on Wednesday agreed to offer temporary shelter to thousands of Rohingya who have landed on their shores and thousands more believed to be stranded in the Andaman Sea. It’s a one-year temporary refuge. Indonesia says Bangladeshis, who are believed to be economic migrants mixed with the Rohingya on refugee boats, will be repatriated.

Malaysian Prime Minister Najib Razak said this week that he had ordered the navy and the coast guard to conduct search and rescue operations for boats carrying Rohingya migrants stranded at sea.

“We have to prevent loss of life,” Najib said in a tweet.

The Myanmar government said Thursday it would attend a regional meeting on the Rohingya humanitarian crisis next week. Earlier it had hinted that it might skip the May 29 meeting in Bangkok in neighboring Thailand — which will bring together more than a dozen governments from Southeast Asia and beyond.

Al Jazeera and wire services