North Korea's execution of leader Kim Jong-un's uncle Jang Song-thaek is expected to have a significant impact on ties with its biggest ally.
In a stunning downfall, Jang - the country's unofficial number two and its key figure in ties with China - was executed on Thursday immediately after a special military trial, state news agency KCNA reported.
State media showed a stooped and handcuffed Jang being led away from the military trial, flanked by two officers, one of whom had a hand on the back of his neck.
Pyongyang's statement called him "worse than a dog" and "despicable human scum" who planned a military coup - rhetoric often reserved in state propaganda for South Korean leaders.
Jang let in "undesirable and alien elements" to a department of the party's crucial Central Committee in a bid to "rally a group of reactionaries to be used by him for toppling the leadership of the party and state".
Two of the crimes that Jang was accused of appear to have been aimed at China.
He was accused of allowing his cronies to sell off the country's valuable resources, including coal.
Jang also allegedly sold land rights in the Rason special economic zone to China for 50 years in order to repay debts he had owed to mineral brokers who had cheated him.
Jang was the major figure driving the development of the Rason special economic zone. In August, a Jilin-based company called Yatai Group signed a 50-year contract to develop a 500,000 square metre plot there.
Cai Jian, the deputy director of Fudan University's Centre for Korean Studies, said that by mentioning the two China-related crimes Kim could be venting his frustration over Beijing's recent condemnation of his nuclear and missile tests.
"North Korea does not really trust China," Cai said. "It doesn't want to overly rely on China because it doesn't want China to control it. But at this point North Korea has no better option than to depend on China."
He said Pyongyang had sent envoys to China earlier this year to discuss the possibility of a state visit by Kim but Beijing had rejected the request.
Chinese foreign ministry spokesman Hong Lei said yesterday the execution was North Korea's internal affair.
"We hope to move forward this relationship on a healthy and sustainable track," Hong said.
The removal of a key interlocutor between China and North Korea's economic ties and Pyongyang's indirect criticism of Beijing in Jang's verdict could slow down or temporarily halt the two countries' economic co-operation, observers say.
"China will be concerned about any uncertainty brought by the personnel reshuffles," said Li Kaisheng, an associate research fellow with Shanghai Academy of Social Sciences. "This outweighs issues over economic co-operation. Stability in North Korea will be China's top priority now.
"Beijing will be closely watching personnel reshuffles and pondering how to continue communicating with North Korea, especially who it should talk to in the future," Li said.
US State Department deputy spokeswoman Marie Harf said Jang's execution was "another example of the extreme brutality of the North Korean regime", adding that Washington was following developments closely.
South Korea yesterday expressed "deep concerns" over the developments and said it would prepare for "all possibilities in the future" and co-ordinate closely with its allies.