Environment Minister Adenan Satem said the haze, which appeared last week, is concentrated over the Klang Valley site of Malaysia's main city, Kuala Lumpur, the administrative capital and a sprawling residential area.
"The situation is not getting better. It is getting worse," the minister said. He said he was going to Indonesia for talks with officials in hopes of finding a solution.
Flights at the Subang airport near Kuala Lumpur, used primarily by charter and private aircraft, were suspended after visibility plunged to less than 1,300 feet, said Daud Hosnan, senior operations manager for Malaysia Airports.
Visibility was better at Kuala Lumpur International Airport, and no flights were affected, Daud said. In downtown Kuala Lumpur, where the smoke even filtered into air-conditioned offices, nothing could be seen beyond 1,500 feet.
Northport, one of Malaysia's key western harbors facing the Malacca Strait, announced it was suspending operations until visibility improves.
The Meteorology Department said no respite was expected until October, when rains would help wash away the haze, a cocktail of dust, ash, sulfur dioxide and carbon dioxide.
An Environment Ministry statement said air quality in three places, including the Kuala Lumpur suburb Shah Alam, has become "hazardous." The air in the administrative capital, Putrajaya, and another Kuala Lumpur suburb, Petaling Jaya, was categorized as "very unhealthy."
Hospitals reported a spike in respiratory and eye ailments from the dust and smoke.