The Regional Comprehensive Economic Partnership (RCEP), the world's largest free trade agreement, officially came into force on Saturday. The agreement came into effect with a first batch of 10 countries, including six of the Association of Southeast Asian Nations (ASEAN) members -- Brunei, Cambodia, Laos, Singapore, Thailand and Vietnam, together with China, Japan, New Zealand and Australia. The agreement will enter into force on February 1 for South Korea, according to a statement by the ASEAN Secretariat on Saturday.