Illustration: Liu Rui/GT

North Korea's fourth nuclear test seems pending, if not imminent. Judging by its past behavior, a launch of intercontinental ballistic missiles (ICBMs) or "satellites" as the North claims is a logical choice before playing with the biggest flame, a nuclear test.

The talk among leaders of China, South Korea, and the US has been on how they should cooperate in preventing the North's fourth nuclear test and managing the aftermath in case prevention fails.

The US made its firm and irreconcilable stance known in Seoul during President Barack Obama's recent visit. Obama warned Pyongyang to expect devastating consequences of further isolation and harsher sanctions.

Seoul also phoned Beijing for a candid talk on the matter as alarming evidence of preparation for nuclear test continued to surface in the test site of North Korea.

Obama in Tokyo during his recent tour also urged Beijing to realize the criticality of its cooperation in pushing Pyongyang into a "different direction."

In the end, South Korea and the US agreed that a sincere measure for denuclearization efforts must be conveyed from Pyongyang as a critical prerequisite to the resumption of the Six-Party Talks.

Realistically speaking, North Korea's fourth nuclear test is inevitable and several more will come. Conventional study shows that it takes at least six tests before a state becomes a nuclear power.

This was the case with India. Pakistan was next with seven. It is safe to assume that there will be at least three or four more nuclear tests coming from North Korea.

How much longer can we tolerate North Korea's nuclear behavior? Do we have enough patience or are the sanctions currently imposed on Pyongyang simply ineffective? Obviously sanctions are being defied by the North's missile shots all over the Korean Peninsula. What will it take for North Korea to realize the devastating consequences of defiance?

It is time for China to make North Korea realize such consequences by pressing harder with sanctions. Should the fourth nuclear test occur, it would mean China's verbal warnings are meaningless and unheard to the ears in Pyongyang.

At the end of the day, it would be true that the time for China to take more assertive action against North Korea with punitive measures, such as sanctions, has arrived. 

China obviously cannot handle North Korea alone. It will require close consultation, cooperation and collaboration with South Korea and the US. Since they are on the same page on the Six-Party Talks and post-test measures, if not prevention ones, China must invite them to be part of its scheme on North Korea.

China's ideas of prevention must be heard by the US and South Korea. How it envisions the prospective resumption of the Six-Party Talks must be discussed in-depth. China must effectively persuade the two countries on its notion of "unconditional resumption" of the Six-Party Talks.

China, the US and South Korea must act together if they were to truly prevent North Korea from conducting the fourth nuclear test.

This cannot happen without support and cooperation from Beijing. Seoul and Washington may share the same stance and yet it will have to be sold to Beijing.

Hence, more than any other times, closer consultation and cooperation are in great demand.

Toward this end, South Korean President Park Geun-hye has already conveyed a message to Chinese President Xi Jinping to hold talks as soon as possible.

The international community awaits China's invitation for collaboration on North Korea.

The author is professor at Kyung Hee University and visiting fellow at the Brookings Institution. opinion@globaltimes.com.cn