South Korea, China and Japan adopted a joint declaration Monday that sums up annual summit talks between their leaders held the previous day, but the document made no mention of North Korea and its provocative behavior.

The omission of any clause on North Korea highlights the difference that the South and Japan have with China over how to deal with Pyongyang. Beijing, the North's last-remaining major ally that provides aid and diplomatic support, has been reluctant to openly criticize Pyongyang.

The three sides had been expected to urge North Korea to refrain from further provocations after last month's long-range rocket launch amid concern the Pyongyang regime could attempt to further escalate tensions with a nuclear test, further missile launches or other provocations.

The 50-point declaration called for the three countries to immediately launch preparations to kick off official negotiations this year on a three-way free trade agreement.

The envisioned pact, if realized, would create one of the world's largest markets as South Korea, China and Japan account for 20 percent of the global gross domestic product (GDP), 17.5 percent of all global trade, and 22 percent of the global population.

The declaration also called for deepening mutual political understanding and trust, deepening economic and trade cooperation, facilitating sustainable development and expanding cooperation in social, cultural and other areas.

The three sides also welcomed Sunday's signing of an investment guarantee treaty that calls for providing most-favored-nation status and other protective measures for investment from each other. (Yonhap News)