But a senior official of the Department of Foreign Affairs said that while China’s accession to the Asean treaty was a welcome development, the Philippines should not “lower its guard” because the pact has no reference to the specific disputes in the South China Sea, such as the Spratlys issue between the Philippines and China.

The diplomat also said the dispute settlement mechanism of the treaty is “largely untested.”

Counselor Wang Jinfeng, Chinese representative to the Asean secretariat in Jakarta, Indonesia, presented the Instrument of Ratification of the Third Protocol Amending the Treaty of Amity and Cooperation (TAC) in Southeast Asia to Sayakane Sisouvong, Asean deputy secretary-general for the Asean political-security community.

China is already one of the 18 high contracting parties to the treaty.

The TAC, adopted by Asean in 1976, prevents signatory nations from engaging in military aggression against neighbors and other activities that disturb peace and stability in the Southeast Asian region.

Asean groups the Philippines, Malaysia, Brunei and Vietnam, which are claimants to parts of the disputed islands in the South China Sea. Other Asean members are Indonesia, Thailand, Cambodia, Laos, Singapore and Myanmar.

The treaty was amended to allow Asean dialogue partners like China to accede to it. Further amendments to the TAC are also under way to allow regional blocs such as the European Union to accede to the treaty.

A senior official of the foreign office said China’s accession to the Asean TAC is expected to allow China to enter into multilateral dialogue being pushed by Asean members.