While China has consistently supported UN sanctions against North Korea, one expert said it had an ambivalent relationship with its southern neighbor and that Sino-North Korean relations had deteriorated since Kim Jong Un came to power in 2011.
"China's priority is stability in the region, as well as domestic stability, and part of that is an alliance with its neighbor North Korea," Alison Evans, deputy head of Asia-Pacific country risk at IHS Markit, told CNBC on Thursday.
"However, North Korea is a bit like a belligerent little brother causing trouble for China," she said, noting that a number of North Korea's missile tests this year had occurred during China's hosting of high-profile events.
"By doing this, North Korea has caused China to lose face and it just shows that North Korea is not behaving in a way that keeps its allies in mind," she said.
Implementing sanctions, then, has been a way for China to "punish" North Korea and yet it has suggested it was prepared to defend the country if the U.S. attacked it, according to an editorial in Chinese state run newspaper The Global Times.
Evans noted that, ultimately, for China it was important to secure its strategic interests, and that meant stopping U.S. influence spreading in the region.
"China would defend North Korea not because it's an ally but because it's in China's strategic interests to have an allied Communist state as a buffer state rather than a Korean peninsula unified under a South Korean flag," she said.
China is not the only country ready to defend North Korea from foreign, and particularly U.S., interference. Foreign Minister Sergey Lavrov said Thursday that the U.S. could have deliberately provoked North Korea to take tough actions, according to Russian state news agency TASS.
"Washington's recent steps seem to be deliberately aimed at provoking Pyongyang to take some tough actions," he said. The U.S. should openly say if its provocative actions are aimed at destroying North Korea," he added, according to the news agency.