- 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.
- Contributes to ASEAN community building.
- Participates in meetings related to ASEAN, including the ASEAN Summit, ASEAN Coordinating Council (ACC) Meetings, ASEAN Political-Security Community (APSC) Council Meetings, ASEAN Socio-Cultural Community (ASCC) Council Meetings, ASEAN Foreign Ministers' Meetings (AMM), the Post Ministerial Conferences (PMC), 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-EU relations for a period of 3 years (July 2009 - July 2012). The Department is, therefore, responsible for the coordination of all aspects of ASEAN relations with the EU and acts as a link with other ASEAN Member States on matters pertaining to ASEAN-EU dialogue relations.