Asean leaders have approved a joint haze monitoring system, Minister for the Environment and Water Resources Vivian Balakrishnan said on Wednesday.

The $100,000 monitoring system was developed by Singapore and is expected to make use of land concession maps from each country, hot-spot data and high resolution satellite images to pinpoint companies responsible for burning land illegally. Fires in Indonesia have led to Singapore's annual haze.

"We hope the respective ministries will upload the digitised concession maps as soon as possible. It will send a strong signal to all companies that they will be held accountable," said Dr Balakrishnan in a Facebook post.

Dr Balakrishnan, Prime Minister Lee Hsien Loong and Law Minister K Shanmugam are attending the 23rd Asean Summit and related meetings in Brunei from Wednesday to Thursday.