The Regional Comprehensive Economic Partnership (RCEP) agreement was signed among its 15 participating countries Nov 15, launching the world's biggest free trade bloc.

Participating countries include the 10 member countries of the Association of Southeast Asian Nations and China, Japan, South Korea, Australia and New Zealand.

The signing of the RCEP is "a victory of multilateralism and free trade," Chinese Premier Li Keqiang said Sunday.

Li's remarks came as he attended the fourth RCEP Summit, held via video link.

"The signing of the RCEP is not only a landmark achievement of East Asian regional cooperation, but also a victory of multilateralism and free trade," Li said.

The 15 participating countries of the RCEP account for around 30 percent of the global population, global gross domestic product and global trade.

The RCEP agreement will accelerate the building of the ASEAN economic community and thereby allow ASEAN to become dynamic and strong partners in promoting cooperation for shared prosperity, Vietnamese Prime Minister Nguyen Xuan Phuc said at the signing ceremony held via video conference.

The signing came after more than 30 rounds of negotiation, which was launched in November 2012, as well as a number of specific leaders and ministerial meetings between the participating countries.

The ongoing 37th ASEAN Summit and related summits take place from Thursday to Sunday via video conferences.

Founded in 1967, ASEAN groups Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Vietnam. Vietnam is the ASEAN chair for 2020.