Officials in China have expressed frustration with communist ally North Korea, according to leaked classified US diplomatic cables.
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 peninsula should be reunified under Seoul's control, they suggested.
The revelations come as regional tensions remain high after the North shelled a South Korean island a week ago.
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.
China has responded to the leaks by urging the US to "properly handle relevant issues," a foreign ministry official said on Tuesday. BBC News
