Southeast Asia, Australia 'gravely' concerned by North Korean weapons

Laos' Prime Minister Thongloun Sisoulith, Indonesia's President Joko Widodo, Cambodia's Prime Minister Hun Sen, Brunei's Sultan and Prime Minister Sultan Bokliah, Thailand's Prime Minister Prayut Chan-O-Cha, Australia's Prime Minister Malcolm Turnbull, Singapore's Prime Minister Lee Hsien Loong, Vietnam's Prime Minister Nguyen Xuan Phuc, Philippines' Secretary of Foreign Affairs Alan Peter Cayetano, Myanmar's State Counsellor Aung San Suu Kyi and Malaysia's Prime Minister Najib Razak wave as they stand together during the Leaders Welcome and Family Photo at the one-off summit of 10-member Association of Southeast Asian Nations (ASEAN) in Sydney, Australia, March 17, 2018. REUTERS/David Gray

SYDNEY (Reuters) - Southeast Asian countries and Australia said on Sunday they held "grave concerns" about escalating tension caused by North Korea's nuclear and missile programmes and urged "irreversible" denuclearisation.

North Korea is pursuing its weapons programmes in defiance of U.N. Security Council sanctions and has boasted of its plans to develop a missile capable of hitting the U.S. mainland.