Japan will propose the creation of a joint task force with the Association of Southeast Asian Nations to fight terrorism and deal with other cross-border issues, diplomatic sources said Friday.

Prime Minister Junichiro Koizumi is expected to make a formal proposal at a summit of ASEAN leaders Tuesday after details of the proposal are worked out with senior officials meeting Saturday in Phnom Penh.

Japan has been working with ASEAN to combat piracy in Southeast Asia. Tokyo now hopes to expand the scope of security cooperation following increased terrorist threats in Asia, as seen in the bombing of a Bali nightclub Oct. 12.