WikiLeaks, the whistleblower's website, has published memos that allege Chinese officials are increasingly exasperated with North Korea and that the reclusive state may be losing its strategic value for Beijing.
According to one memo, the Chinese ambassador to Kazakhstan revealed that Beijing considers the North's nuclear programme to be "very troublesome".
The leaked cable, quoted in AFP, revealed US Ambassador Richard Hoagland saying that Ambassador Cheng Gouping "said China hopes for peaceful reunification in the long-term, but he expects the two countries to remain separate in the short-term."
China's response to the leaks were very tact only urging the United States to "properly handle" the issue.
"We hope the US side will properly handle relevant issues," foreign ministry spokesman Hong Lei said when asked about the leaks, adding that Beijing did not "want to see any disturbances to China-US relations."