JAKARTA (THE JAKARTA POST/ASIA NEWS NETWORK) - An Indonesian forestry expert has called on haze-affected Asean countries such as Malaysia and Singapore to do more to deal with forest fires by stepping up enforcement of their companies operating in Indonesia.

The remarks by Herry Purnomo, a scientist at the Center for International Forestry Research (Cifor) and professor at Bogor Agricultural University, came as Indonesia has so far declined Singapore's offer of help to fight the forest fires.

"About 50 per cent of palm oil companies operating in Indonesia are owned by Malaysians and Singaporeans," Herry told The Jakarta Post on Monday.

According to Herry, Indonesia has at least 11 million hectares of palm oil plantation spread across the islands, from Sumatra to Papua.

A number of palm oil companies clear land by burning it in order to reduce production costs, Herry said.

Herry said that Indonesia, Malaysia and Singapore should issue regulations and law enforcement for their citizens' companies operating in Indonesia.

He added that they should also allocate up to US$10 billion (S$14 billion) to cope with the forest fires in Sumatra and Kalimantan.

"The cost is equal to the estimated total economic losses resulting from the recent smog," Herry told the paper.

Herry said that Indonesia was estimated to suffer US$4 billion in losses this year, in terms of agriculture production, destruction of forest lands, health, transportation, tourism and other economic endeavors.

A 2013 World Bank report showed that the total financial loss from forest fires in Riau province amounted to Rp 20 trillion.

"The funding allocated to handling forest fires is very small. It is about a hundred thousand dollars. How can we manage to do anything with such little funding and such a huge problem like the forest fire issue," he said.

Forest fires and smog have become an annual problem for Indonesians due to improper practices of plantation companies in doing business, Herry said.

Herry said that the forest fires, which always occurred during the dry season, mostly in Sumatra and Kalimantan, had never been handled satisfactory over the past two decades.

"This year forest fires are the worst since 1997," he said.