- The national focal point on ASEAN related matters.
- The repository of information on all ASEAN matters at the national level.
- Coordinates the implementation of ASEAN decisions at the national level.
- Coordinates and supports the national preparations of ASEAN meetings.
- Promotes ASEAN identity and awareness at the national level.
- Participates in meetings related to ASEAN, including the ASEAN Summit, ASEAN Coordinating Council (ACC) Meetings, ASEAN Political-Security Community (APSC) Council Meetings, ASEAN Foreign Ministers' Meetings (AMM), the Post Ministerial Conferences (PMC),East Asia Summit (EAS), the ASEAN Regional Forum (ARF), Joint Preparatory Meetings (JPM) and ASEAN Senior Officials (SOM) Meetings.
- Participates in ASEAN Meetings with its Dialogue Partners and meetings with other regional and international organizations.
- Coordinates with relevant national lead agencies and Brunei Darusalam's Permanent Mission to ASEAN in Jakarta on ASEAN matters.
- Works closely with the ASEAN Secretariat in Jakarta and the National Secretariats of other ASEAN Member States.
Brunei Darussalam is currently the country-coordinator for ASEAN-India relations for a period of 3 years (July 2012 - July 2015). The Department is, therefore, responsible for the coordination of all aspects of ASEAN relations with the India and acts as a link with other ASEAN Member States on matters pertaining to ASEAN-India dialogue relations.