During the meeting, which marked the resumption of the trilateral leaders' meeting mechanism after a two-and-a-half-year hiatus, the three sides agreed to meet on a regular basis to expand their common interests and manage disputes.
China, Japan and South Korea are three big economies in the world, and are each other's key partner in trade and economic cooperation, said the Chinese premier, adding that they shoulder great responsibilities for boosting regional development, guiding regional economic integration and safeguarding regional peace and stability.
Strengthening trilateral cooperation, Li said, not only meets the needs of the three countries, but also accords with the expectations of the region and the international community at large.
Abe, for his part, pledged Tokyo's adherence to free trade. He said that as major traders in the world, the three sides all support free trade and open markets.
He called upon the three countries to come up with high-level trade rules that suit the current circumstances in the 21st century.
Meanwhile, Moon called the three nations inseparable cooperation partners, and said he hopes that the content of trilateral cooperation can be enriched.
The leaders' meeting came as some developed countries are retreating from free trade and threatening to flog others with soaring tariffs.
Against this background, China, Japan and South Korea can become important forces for promoting trade liberalization, said Tatsuhiko Yoshizaki, chief economist at Japan's Sojitz Research Institute.
"The world needs more voices calling out the fact that trade is not a zero-sum game, but win-win (cooperation)," Yoshizaki said.