At the 10th Association of Southeast Asian Nations (ASEAN)-China Summit, Wen said claimant countries should actively engage in the joint development of Spratlys in the South China Sea.
"We should actively implement the Declaration on the Code of Parties in the South China Sea to promote practical cooperation in the South China Sea and ensure its stability," Wen said.
A breakthrough in the negotiations for a code of conduct was achieved in Cambodia in 2002. The claimant countries agreed to the adoption of the Declaration on the Conduct of Parties in the South China Sea instead of a Regional Code of Conduct.
The non-binding code provides that the claimants should exercise self-restraint in activities in the Spratlys.
China, the Philippines, Brunei, Malaysia, Vietnam and Taiwan are claimants in the Spratlys that is believed to be rich in oil deposits.
The ASEAN renewed on Friday its call on China to sign and adopt a Code of Conduct in the South China Sea.
Foreign Affairs Secretary Alberto Romulo urged Beijing during the ASEAN-China ministerial meeting to move the agreement on joint marine and seismic undertaking in the South China Sea to a higher level by adopting a code of conduct in the disputed Spratlys.
"We want to move it to a higher level from declaration and have a code of conduct," Romulo said.
"ASEAN and China acknowledged the importance of keeping faith with the ASEAN-China Declaration on the Conduct of Parties in the South China Sea. I emphasized that this document remains at the heart of cooperation between ASEAN and China in terms of ensuring that an atmosphere of peace remains in the South China Sea in spite of the conflicting claims in the area," he added.
Romulo called for more progress in the work of the Joint Working Group under this declaration.
He said this move was welcomed and supported by Chinese Foreign Minister Li Zhaoxing, who thanked the Philippines for the cooperation shown in implementing the declaration.