The latest disclosures from leaked classified US diplomatic cables suggest some Chinese officials have been losing patience with their North Korean allies.
A South Korean diplomat quoted two high ranking Chinese representatives as saying that Beijing would be prepared to accept a reunified Korea under the South's control, as long as it was not hostile to China.
Pyongyang was behaving like a "spoiled child", a Chinese foreign ministry official is quoted as having said in 2009, in cables released by WikiLeaks.
Officials reportedly told South Korean counterparts that Beijing placed little value on the North as a buffer state.
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.
Meanwhile, WikiLeaks' founder Julian Assange has told Forbes magazine a fresh "mega leak" early next year will target a major American bank early next year.
Comparing the documents to the emails that exposed Enron's dealings amid its collapse, Mr Assange the thousands of documents could "take down a bank or two."