China has sounded out Japan and South Korea to hold a trilateral summit again in December in Beijing, hoping to further ramp up cooperation to denuclearize North Korea, diplomatic sources said Sunday.

With the leaders of Japan, China and South Korea having met for a summit in Tokyo just last month, it is unusual for a trilateral meeting at this level to be held again in the same year.

China, a key economic benefactor of North Korea, appears to be pushing for a successive summit with its neighbors to ensure that it has the lead in the North Korean nuclear issue, following the recent historic U.S.-North Korea summit, some political commentators say.

Last Tuesday, U.S. President Donald Trump and North Korean leader Kim Jong Un held a summit in Singapore during which Kim promised to work toward the "complete" denuclearization of the Korean Peninsula.

It was the first-ever summit between a sitting U.S. president and a North Korean leader.

The Chinese government also told Japan that it will receive Prime Minister Shinzo Abe for an official visit to China around the time of the envisaged trilateral summit, the sources said.

When Abe, Chinese Premier Li Keqiang and South Korean President Moon Jae In met in May, they agreed to work together toward the complete denuclearization of North Korea. Meeting Li bilaterally, Abe expressed a desire to visit China by the end of this year.

By organizing a second trilateral summit this year, China may want to demonstrate the partnership between the three Northeast Asian countries to the United States, as Beijing and Washington have been increasingly mired in a trade dispute.