Philippine President Benigno Aquino urged Southeast Asian countries Thursday to present a united front to China over the South China Sea at an upcoming regional summit.
Aquino said all 10 members of the Association of Southeast Asian Nations should speak with one voice at the East Asia summit in Cambodia next week.
"We can talk to the other claimants that aren't ASEAN members but since we want to maintain ASEAN's centrality, we must have just one voice in ASEAN... in this regard," he told reporters.
He noted that ASEAN included four countries with some overlapping claims to islands and waters in the South China Sea -- the Philippines, Brunei, Malaysia and Vietnam. Non-members China and Taiwan also have their own claims.
ASEAN also includes Cambodia, Indonesia, Laos, Myanmar, Singapore and Thailand.
China insists it has sovereign rights to nearly all of the South China Sea despite the competing claims of the four ASEAN members to parts of the waters.
In July a regional ministerial meeting in Phnom Penh ended in disarray over the issue.
ASEAN chair Cambodia, a close China ally, refused to allow Vietnam and the Philippines to mention specific disputes with China over the sea, preventing the group from issuing a joint communique for the first time in its 45-year history.
Aquino said he hoped other countries outside of ASEAN realised it was necessary to maintain stability in the South China Sea for the region's growth to continue.
Tensions over the sea have risen in recent months, with Beijing becoming embroiled in diplomatic rows with Manila and Hanoi.