Bangkok: Thailand expressed concern on Monday at a wave of anti-migrant vitriol on social media, which the government said underlined why it cannot accept any more of the asylum seekers who have been arriving by boat on its shores.

The United Nations has urged Southeast Asian governments to mount a coordinated rescue operation for thousands of desperate Bangladeshis and Rohingya Muslims from Myanmar adrift in rickety boats in the Andaman Sea.

But Thailand, Malaysia and Indonesia have made it clear that migrants are unwelcome and towed overcrowded boats away from their shores in recent days.

Following an appeal from US Secretary of State John Kerry, Thailand's junta said it would set up temporary shelters for those that did make it ashore, prompting an outpouring of bile on social media from those who do not want migrants to stay.

‘Prime Minister Prayuth Chan-ocha is worried about the social media trend right now that shows that the government should not help irregular migrants in the Indian Ocean because of concerns that they will be a burden on Thailand in the long-term,’ Colonel Sansern Kaewkamnerd, deputy government spokesman, said on Monday in a statement.

‘Whatever the government's decision, the needs of Thailand and the Thai people will come first and we will take on no policy that affects the welfare and security of the country.’

Many in Thailand are calling for Washington to intervene, using the hash tag #USAMUSTHelpRohingya.

‘You said we don't have humanity, if you've it, then just let them stay in ur country. Always nosy with other countries. #USAMUSTHelpRohingya,’ one Twitter user, @IcezPandadang, wrote in English.

Another Twitter user said he was worried about the discovery of more than 100 migrants on Friday in Thailand's southern province of Phang Nga.

‘I'm not panicking much only that 106 have landed in Thailand. I'm not worried about much except a cycle of crime and pregnancy,’ wrote @My_int.

A clampdown by Thailand's military rulers has made a well-trodden trafficking route into Malaysia too risky for criminals who prey on Rohingya fleeing persecution in Buddhist-majority Myanmar and on impoverished Bangladeshis looking for work.

Traffickers have abandoned their boats in the Andaman Sea, leaving thousands thirsty, hungry, sick and without fuel.

Vitriol directed at Rohingyas was particularly worrying, said Thai author and social media commentator Kaewmala, who goes by a screen name to protect her identity.

‘There is a lot of fear and hatred based on pervasive nationalistic sentiment and xenophobia,’ she told Reuters. ‘It is very disappointing to see.’

In Malaysia, some also took to social media to express concern over the migrant influx.

In predominantly Muslim Indonesia, where more than 1,400 migrants from Bangladesh and Myanmar have been brought to shore over the past week, the migrants have been met with a warmer reception.

‘Look at the problem from a religious angle, if nothing else,’ said Mustafa, a local fisherman from Indonesia's Aceh province. ‘They must be helped.’