The Regional Comprehensive Economic Partnership, or RCEP, will come into effect in January. The free trade agreement will include 15 Asia-Pacific economies.

The deal was signed last November by Japan, China, South Korea, Australia, and New Zealand, along with the 10 members of the Association of Southeast Asian Nations.

Japan's Foreign Ministry officially announced that the partnership would come into force on January 1. This comes after Australia and New Zealand sent documents to the ASEAN Secretariat notifying they've completed their domestic procedures.

RCEP will cover about 30 percent of the world's population and gross domestic product.