China is exploring whether to change tactics in engaging with North Korea, which is becoming increasingly unpredictable since Kim Jong-un came to power, observers and analysts say.
The development comes as the foreign ministry in Beijing sent two delegations to Pyongyang in less than a month - a move that scholars and government think tanks say is aimed at seeing whether North Korea still holds China as its staunchest ally.
The motives behind Pyongyang's actions over the past year - from nuclear tests to the high-profile execution of Kim's uncle Jang Song-thaek - have mystified many in the region, including China. Many Chinese scholars and government think tanks say they are being kept in the dark about its latest developments.
Contact between Beijing and Pyongyang under the younger Kim is not as high profile as under his father Kim Jong-il, and the execution of Jang - a key figure in North Korea's economic engagement with China - has triggered worries that North Korea no longer highly regards its ties with China, said Cai Jian , deputy director of Fudan University's Centre for Korean Studies.
The visits to Pyongyang by the Chinese delegations - one headed by Deputy Foreign Minister Liu Zhenmin - will help Beijing gauge whether Pyongyang is still politically stable in the wake of the purge. They also signal that Beijing may seek changes in how it engages North Korea.
The International Department of the Communist Party is the main organisation behind cultivating ties between Beijing and Pyongyang, but Cai said the foreign ministry may now become more involved in contact with North Korea.
"Communications with the International Department usually stresses more on the relationship between the ruling parties … and that usually conveys a sense that the two are brothers or allies," Cai said. "With the involvement of the foreign ministry, it is more like nation-to-nation routine exchanges, stressing less on brotherly ties."
Jia Qingguo , an international relations professor at Peking University, said "nation-to-nation" ties would allow Beijing to deal with North Korea in a more "normal" way, focusing more on China's national interests instead of heavily emphasising ideology. That would clearly spell out under what conditions Beijing would continue to provide aid to Pyongyang.
"China is very upset with the younger Kim," Jia said. "China had expectations he would further open up the North Korean economy, but now it is not sure if such expectations can continue."
One of the accusations made against Jang was that he sold Pyongyang's valuable resources to another country, widely believed to be China. Before the execution, Pyongyang also put China in an embarrassing spot by launching nuclear tests, raising doubts over whether Beijing still held significant influence over Kim's regime.
Pyongyang has recently said it was willing to return without preconditions to the stalled six-nation talks on its nuclear programme.
But Zhang Liangui , a professor of international strategic research at the Communist Party's Central Party School, said Pyongyang's real intentions were unpredictable.
"North Korea has not resorted to provocation mainly because it wants economic aid and for the international community to recognise its nuclear development," Zhang said. "It will make provocative moves again when it has other strategic aims."
Cai said China's access to inside knowledge about North Korea was now limited. On some occasions, Beijing even had to rely on information from non-governmental organisations and politicians from Seoul, making it difficult for Beijing to make accurate judgments about the situation in Pyongyang and to formulate its strategy, he added.
"What North Korea reveals to us is just too little," he said.