The Philippines rejects the "use of force" to undermine its interests in the contested South China Sea but it does not want any conflict and has agreed with China to ease tensions in a contested shoal, officials said on Friday.

"We don't want war," National Security Adviser Eduardo Ano told reporters in Manila.

Ano said efforts were underway to de-escalate tensions in the disputed waterway, where Manila and Beijing have accused each other of aggressive behavior involving their ships and of damaging the marine environment.