Latest disclosures from the whistle-blowing website WikiLeaks include a report in which senior Chinese officials say the Korean Peninsula should be reunited under the South's control.
The two officials reportedly told a South Korean counterpart that China places little value on North Korea as a buffer state, but it would not welcome American military presence in the North.
A series of cables shows American diplomats discussing the possibility of North and South Korea uniting when the North's leader Kim Jong-Il dies, the BBC reports.
The South Koreans say he can not live more than another five years and their vice-foreign minister predicts that when Mr Kim does die, China would not be able to stop the North's collapse.
The minister goes on to claim what he calls "sophisticated" Chinese officials are ready to face a new reality.
The minister says the officials now believe that North Korea serves no purpose to them as a buffer state and they think the peninsula should be reunited with South Korea in charge - as long as the new country was not hostile to China.
The revelations come as regional tensions remain high after the North shelled a South Korean island a week ago killing four people.
The US administration says the WikiLeaks disclosures are an attack on the world community, but that partnerships it had worked hard to build would withstand the challenge.
The whistle-blower website is continuing to drip-feed thousands of diplomatic cables.
It has published a only a few hundred documents, but has made available all 250,000 it says it has obtained to five publications, including the New York Times and Britain's Guardian newspaper, the BBC reports.