ASEAN leaders have endorsed a recommendation by ASEAN environment ministers for a monitoring system for trans-boundary haze, said a press release Thursday. The leaders \"welcomed the adoption of the recommendation...for an ASEAN Sub-Regional Haze Monitoring System (HMS), as a joint haze monitoring system among Sub-Regional Ministerial Steering Committee on Trans-boundary Haze Pollution countries,\" the release quoted as saying a statement by Brunei\'s Sultan Hassanal Bolkiah, chairman of the 23rd ASEAN Summit. The move intended to combat yearly pollution caused by illegal fires that plagues large parts of the region. In June this year, thick haze caused by forest fires, which was used to clear land in Indonesia, blanketed neighboring Singapore and Malaysia, raising air pollution levels to record highs and setting off a diplomatic spat over who should claim responsibility for the fires. At the start of the summit, ASEAN leaders agreed to share satellite data to help them locate and determine fires when they are occurring on land owned by plantation companies. \"We also took note of the outcomes of the trilateral meeting on trans-boundary haze between the foreign ministers of Indonesia, Malaysia and Singapore at the sidelines of the ASEAN Foreign Ministers\' Retreat in Hua Hin on Aug. 14, 2013,\" the statement said. \"We also welcomed Indonesia\'s commitment to the ratification of the ASEAN Agreement on Trans-boundary Haze Pollution and looked forward to Indonesia\'s ratification of the Agreement at the earliest time,\" it added.