Malaysia's Deputy Environment Minister has called for his country's neighbors, especially Indonesia, to take tough steps to fight forest fires that produce haze that often blankets much of Southeast Asia.

Haze from forest fires and open burning on plantations is a persistent problem in parts of Southeast Asia, devastating the environment, disrupting air travel, tourism, and other businesses.

In 1997 and 1998 it cost the region an estimated $9 billion in lost revenue and costs such as health care for those made ill by the bad air.

Malaysia has been among the hardest hit by smoke and dust. In August, air pollution shot to hazardous levels in some parts of the country and forced some schools and airports to close as a state of emergency was declared. Singapore, Indonesia and parts of southern Thailand are also affected.

Malaysian deputy environment minister Sothinathan Sinna says more preventative measures must be taken in countries that are the source of the pollution. He urged Indonesia to ratify a 2002 agreement intended to prevent haze.

Most of the forest fires in Indonesia are started deliberately as a cheap way to clear land. The government in Jakarta says it lacks the personnel and funds to stop the burning. It also says Malaysian plantation owners set many of the fires.

Philippine Environment Secretary Michael Defensor says that while his country is not affected, the issue must be addressed.

"It is really a problem. I understand that in Kuala Lumpur it is a valley. And there is really not much wind. So when you have the haze there it settles down on the area," said Mr. Defensor. "And in the case of Malaysia some schools are canceled and some of the work is called off because of this."

Mr. Defensor says that ASEAN nations have agreed to cooperate on the issue and that it is a worsening problem, but he gave no specifics on ASEAN action in this area.

ASEAN is composed of Malaysia, Indonesia, Singapore, the Philippines, Thailand, Brunei, Cambodia, Laos, Myanmar and Vietnam.