Thai Prime Minister Gen. Prayut Chan-o-cha delivers his keynote speech. Fernando G. Sepe, Jr., ABS-CBN News

MANILA - Thailand wants the "full and effective" implementation of China's agreement with Southeast Asian countries to manage tensions in the South China Sea, its prime minister said Friday.

The 2002 Declaration on the Conduct of Parties calls on all parties to exercise "self-restraint" and avoid complicating the maritime dispute over the vital trade route.

"Thailand also attaches great importance to the full and effective implementation of the DOC to foster cooperation in various areas," Prime Minister Prayut Chan-o-cha told a select group of reporters through an interpreter.

"I can assure you that all the ASEAN leaders agree that we all must be restrained."

Beijing, which claims most the South China Sea, has been criticized for building artificial islands replete with a weapons system in the disputed waters despite the DOC.

Prayut said China and the Association of Southeast Asian Nations (ASEAN) would seek to finish a framework document by June this year.

The Thai leader cited the importance of the document as a "basis" for crafting a more detailed and binding code of conduct to help manage maritime tensions.

Prayut did not address concerns over Philippine President Rodrigo Duterte's statement that China's arbitration defeat would not be tackled during the Manila-led ASEAN meetings this year.

Duterte was previously urged to take advantage of the Hague-based arbitral ruling during negotiations for a code of conduct with China.

The ruling invalidated the basis of Beijing's sweeping claims over the South China Sea.

Asked if the regional bloc should specifically call on China to stop its land reclamation and militarization activities, Prayut said he was "well aware of the very productive outcome of the meetings" in Manila.

He said he "supports the ASEAN gesture or ASEAN decision whatever it may be."

In its statement last year, ASEAN made no mention of China when it "took note of the concerns expressed by some leaders" on the matter.

Prayut maintained the maritime dispute must be resolved peacefully using mechanisms under international law.