China has temporarily halted its diplomatic exchanges with North Korea in protest of the North's second nuclear test and its recent hard-line policies.

According to sources in Beijing, Chinese officials canceled Monday a visit to North Korea by Chen Zhili, the vice chairwoman of the Standing Committee of the National People's Congress.

In addition, other official visits by Chinese delegations to Pyongyang will be postponed and visits to Beijing by North Korean officials will be boycotted.

China also scrapped a plan to dispatch to Pyongyang a delegation led by the head of its Communist Party International Department, Wang Jiarui.

The delegation had been tasked with persuading North Korea to return to the six-party nuclear talks.

Only a minimum-level diplomatic channel will remain in operation between China and North Korea for the time being.