Although ties have been strained in recent times by their territorial and historical disputes, leaders of Japan, China and the Republic of Korea struck a more harmonious note in Tokyo on Wednesday.

Which is not surprising as the trilateral summit came hard on the heels of the positive progress that has been made in efforts to bring the Democratic People's Republic of Korea in from the cold. And the efforts Beijing and Tokyo had been making to build on their shared interests to kick-start their stalled relations.

Indeed, when Premier Li Keqiang, Japanese Prime Minister Shinzo Abe and ROK President Moon Jae-in sat down for talks, the portents for joint efforts to promote regional peace and stability and greater economic integration were the most promising they have been for years.

The fact that they reached a consensus on the need for complete denuclearization of the Korean Peninsula and the permanent establishment of peace shows that there is common ground to be found. And there is much the three neighboring countries could achieve if they could shelve their differences and work together. Certainly in trade, where a tripartite free trade agreement is long overdue.

For despite the fact that their combined markets account for more than 20 percent of the global gross domestic product, intra-regional trade among the three is only 20 percent of their total trade. Clearly there is much potential to be tapped.

And tapping that potential has become even more urgent in the face of the United States' protectionist stance on trade.

Reports that they have agreed to work toward finalizing an FTA and the proposed Regional Comprehensive Economic Partnership with Southeast Asian nations hopefully mark progress toward realizing what would give significant boosts to the regional economy.

However, as Premier Li said on Wednesday, China-Japan ties are at a crucial stage for improvement, as this year marks the 40th anniversary of the signing of the bilateral treaty of peace and friendship. That opportunity should not be wasted. The two countries should uphold the principles of the four basic documents that form the foundation for better ties.

The meeting shows that where there is conviction and certainty in the goals to be achieved, the three countries can find words of shared resolve. Now the three should ensure their conduct is in accordance with their expressed intentions.