But even as the 10 Asean member states signed the deal, fires in Indonesia had reportedly spread haze over Borneo island, causing breathing problems and eye irritations.
The agreement calls on countries to strengthen their firefighting forces, enforce controls on open burning and establish early warning systems to stop the spread of polluting smoke.
Negotiations on the deal began five years ago, after forest fires cast a thick pall of smoke over much of the region, causing $9.3bn in economic losses.
Regional problem
"The haze was not too thick but we fear that as the dry season continues, things will get worse between August and September," said an official at the meteorology office in Indonesia's Central Kalimantan province, where fires had broken out on Monday.
Signatories
Brunei
Burma
Cambodia
Indonesia
Laos
Malaysia
The Philippines
Singapore
Thailand
Vietnam
The blazes were blamed on farmers who often illegally light open fires as a cheap way to clear land.
The Indonesian Government has had little success in enforcing bans on open fires.
Fires on Sumatra and Borneo regularly spread smoke to neighbouring Singapore and Malaysia.
Monday's agreement - the first regional convention of its kind - should bind governments to enforce controls, but there are no penalties for countries which do not comply.