One diplomatic cable disclosed that China’s vice foreign minister told US officials that Pyongyang was behaving like a “spoiled child” to get America’s attention in April 2009 after carrying out missile tests.
However, the documents also outline a complicated relationship between China and North Korea – with other cables exposing US frustration at how North Korea was able to send weapons equipment to Iran via China.
A senior Chinese official, speaking off the record to American officials, insisted that Chinese influence over North Korea was frequently overestimated.
One of the most crucial conversations is recorded as taking place in February earlier this year between Chun Yung-Woo, the then South Korean vice-foreign minister and Kathleen Stephens, the US Ambassador in Seoul.
Mr Chun claimed that younger generation Chinese Communist party leaders would not risk renewed armed conflict on the Korean peninsula. Mr Chun also alleged that two senior Chinese officials told him that they believed the Korean peninsular should be reunited under South Korea’s control.
"Citing private conversations during previous sessions of the six-party talks, Chun claimed [the two high-level officials] believed Korea should be unified under ROK [South Korea] control,” the US Ambassador reported.
Mr Chun also told the Americans that the two Chinese officials were ready to “face the new reality”.
The latest leaked documents also disclose growing Chinese concerns over North Korea’s growing nuclear ambitions. A Chinese ambassador told the Americans that the regime was a “threat to the whole world’s security”.
Political collapse could also ensue once Kim Jong-il, the leader of North Korea died despite the regime planning for the succession of his son, Kim Jong-un.
However, the Chinese position towards North Korea is complicated by other documents disclosing the country’s apparent role in the regime’s arms dealing.
The US government has repeatedly asked the Chinese to stop shipments transiting between North Korea and Iran through Beijing airport, according to memos sent by both US Secretary of State Hillary Clinton and the former holder of the office, Condoleezza Rice.
The issue was even raised during talks between President George Bush and his Chinese counterparts.
Documents released by the Wikileaks website show that the Americans provided Chinese officials of the exact times and planes on which supplies were being sent from North Korea to Iran.
American officials are told to “insist on a substantive response from China” after the Americans intelligence showed that North Korean engine parts will be sent to Iran from Beijing in November 2007.
The memo listed at least ten occasion when “jet vanes” were flown from North Korea to Iran, through Beijing, on board commercial flights.
In February this year, the current Secretary of State Hillary Clinton again wrote to American officials in Beijing about Iran’s nuclear plans. According to American intelligence, a Chinese company offered to sell gyroscopes produced by a Russian company to Iran.
Mrs Clinton requested that the Chinese government took “all appropriate measures to ensure that [the Chinese company] is not facilitating unauthorized exports of missile technology to Iran.”
The US has repeatedly voiced its concerns about the Iranian nuclear programme, although Iran insists that the developments are peaceful and for energy generation.
Earlier this year, Mrs Clinton again wrote to set out concerns about Iran’s attempts to buy five tons of carbon fibre from a Chinese company. The carbon fibre “could be used to produce rocket nozzles or motor cases for Iran's solid propellant ballistic missile systems,” said officials.