A source in Seoul said, "North Korea asked for help in its pursuit of a declaration ending the war." China favors a peace treaty instead because that will be legally binding on all sides.

Chinese State Councilor Yang Jiechi made a secret visit to Seoul this month and met with South Korea's national security adviser Chung Eui-yong to discuss the issue. Chung then traveled to Washington and China's Vice Foreign Minister Kong Xuanyou visited Pyongyang.

Behind-the-scenes negotiations between the two Koreas, the U.S. and China are underway to declare a formal end to the Korean War.

But North Korea convinced China to back a declaration, which is more practical over the short term, to guarantee the survival of the regime.

Following Yang's visit to Seoul, Chung traveled to Washington between July 20-22 and met White House National Security adviser John Bolton. Kong flew to Pyongyang last week to meet North Korean Foreign Minister Ri Yong-ho. The South Korean government plans to contact Kong to be briefed on his visit to North Korea.

But differences between the four countries are substantial. The South Korean government wants an early declaration to encourage North Korea to denuclearize. But the U.S. continues to demand that North Korea take fundamental steps toward denuclearization first, including submitting details of its nuclear arsenal.

China is refusing to lean heavily on the U.S. One diplomatic source said, "China is concerned that it may be held responsible for delaying North Korea's denuclearization if it spearheads the issue of declaring an end to the Korean War."

The Chinese Foreign Ministry made no mention of ending the Korean War when it announced the results of Kong's meeting with Ri last Thursday.

Shin Beom-chul at the Asan Institute for Policy Studies said, "If China participates in the declaration, it will have to raise issues concerning its own interests like the South Korea-U.S. alliance or American troop presence in the South. That would complicate matters, so the U.S. would probably prefer a bilateral declaration with North Korea."

The foreign ministers of the two Koreas, the U.S. and China are expected to discuss these issues on the sidelines of the ASEAN Regional Forum in Singapore later this week.