Indonesia on Thursday accused Singapore of acting "like a child" over acrid smog from forest fires in Sumatra that has triggered the city-state's worst environmental crisis in more than a decade, as the two nations held talks.

The escalation in tensions between tiny Singapore and its vast neighbour came as the levels of haze enveloping the island hit a new record high, shrouding the whole city, from residential blocks to tree-lined parks.

Singapore ratcheted up pressure on Jakarta Thursday to take "definitive action" to stop the fires -- but Indonesia, which insists Singapore companies that own plantations on Sumatra also share the blame, hit back.

"Singapore should not be behaving like a child and making all this noise," Agung Laksono, the minister coordinating Indonesia's response, told reporters. "This is not what the Indonesian nation wants, it is because of nature."

The minister for people's welfare also insisted that the sprawling archipelago did not want any financial assistance to fight the fires from its rich neighbour unless it was a large amount.

"If it is only half a million, or one million dollars, we don't need that. We would rather use our own national budget," he said.

His comments came as an emergency meeting hosted by Indonesia's foreign ministry in Jakarta and attended by the chief executive of Singapore's National Environment Agency (NEA), Andrew Tan, got under way.

Singapore's air pollution index meanwhile hit a new record high, soaring to 371 at 1:00 pm (0500 GMT), well past the previous high of 321 set the night before.

Any reading above 300 is "hazardous" while a reading above 400 is deemed "life-threatening to ill and elderly people," according to government guidelines.

"This is now the worst haze that Singapore has ever faced," said Vivian Balakrishnan, Singapore's minister for the environment and water resources.

"We need urgent and definitive action by Indonesia to tackle the problem at source," he said on Facebook.

"Singaporeans have lost patience, and are understandably angry, distressed and concerned."

Smog still shrouded the city-state as residents went to work Thursday, and more commuters were seen wearing disposable medical masks than in previous days.

The acrid odour of burnt wood and grass could be smelled in living rooms and bedrooms across the island as well as inside the air-conditioned trains of Singapore's metro system.

Drug stores in the central business district were sold out of disposable masks and refused to take advance orders, telling customers to return the next day in case new stocks arrived.

Parks were empty of the usual morning joggers, but thousands of employees still trooped to offices and labourers continued their work on high-rise buildings under construction.

The previous Singapore air pollutant index high of 226 was recorded in September 1997 at the height of a Southeast Asian calamity also resulting from vast amounts of haze from Indonesia, where slash-and-burn farming generates heavy smoke during the dry season that begins in June.

Parts of Malaysia close to Singapore have also been severely affected by the smog.

Laksono said that plans to use cloud-seeding to unleash rain over Sumatra and put out the fires were also under way, and it was hoped helicopters could be dispatched on Friday.

Smallholders and plantations in Sumatra -- some of them with Singaporean investors -- have been accused of using fire to clear land for cultivation, but big palm oil companies deny involvement in such activities.

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