ASEAN member states Flag Country Capital Area (km²) Population (2004 unless noted) Head of State Head of Government Membership date Brunei Darussalam Bandar Seri Begawan 5,765 374,800 (2004 est.) Haji Hassanal Bolkiah Mu'izzaddin Waddaulah January 7, 1984 Cambodia Phnom Penh 181,035 14,131,000 Norodom Sihamoni Hun Sen April 30, 1999 Indonesia Jakarta 1,890,000 215,960,000 Susilo Bambang Yudhoyono August 8, 1967 Laos Vientiane 236,800 5,758,000 Khamtai Siphandon Bounnhang Vorachith July 23, 1997 Malaysia Kuala Lumpur 330,257 23,671,000 Mizan Zainal Abidin Abdullah Ahmad Badawi August 8, 1967 Myanmar Naypyidaw 676,577 54,745,000 Than Shwe Soe Win July 23, 1997 Philippines Manila 300,000 82,664,000 Gloria Macapagal-Arroyo August 8, 1967 Singapore Singapore City 697 4,198,000 Sellapan Ramanathan Lee Hsien Loong August 8, 1967 Thailand Bangkok 513,254 64,470,000 (2003) Bhumibol Adulyadej Surayud Chulanont August 8, 1967 Vietnam Hanoi 330,363 82,222,000 Nguyen Minh Triet Nguyen Tan Dung July 28, 1995 . ASEAN member states Flag Country Capital Area (km²) Population (2004 unless noted) Head of State Head of Government Membership date Brunei