China will cooperate with South Korea to neutralize North Korea nuclear weapon. Beijing was angered by North Korea nuclear test during financial problem in China. North Korea said that it has successfully test first hydrogen bomb on Wednesday, January 6.

However, some analysts said China is not fully prepared to pressure North Korea because of China's security interest. Kim Hwan-suk, a senior analyst at the South Korean Institute for National Security Strategy told Yonhap News "North Korea used brinkmanship because it knows that China won't abandon North Korea, given its strategic value," Kim said in Seoul. "North Korea expects China to fully join sanctions against the North by the U.N. Security Council."

Although China strongly opposed North Korean nuclear test, China will not abandon North Korea. A commentary from Xinhua news agency criticized U.S. foreign policy for current nuclear crisis. The state-owned news agency said, "The U.S.'s combative approach has in effect deepened Pyongyang's sense of insecurity and prompted the country to go further in challenging non-proliferation restrictions."

One of U.S. combative approach as China mentioned is the over-reaction of U.S. Foreign Minister John Kerry that urged China to support a more aggressive approach with Pyongyang.

However, North Korea's defiant action to test its nuclear weapon in the midst of economic crisis showed that Pyongyang has been a serious threat to China. Zhang Liangu, professor of international strategy studies at the Central Party School in Beijing told South China Morning Post that, "Most Chinese used to believe that Washington and Pyongyang were the key players in North Korea's nuclear problem, with Beijing just the middleman. But as North Korea has developed its own nuclear weapons, China is a major victim."

The fourth North Korean nuclear testing was conducted very close to the border with China. Tremor from the detonation was felt at the Jilin province in northeast of China, prompting the evacuation of some local schools and office buildings. Some analysts in China also confirmed that Pyongyang has become so unpredictable that no one could foresee who were its friends or enemies.

Therefore, Chinese and South Korean officials have engaged in a dialogue to disarm North Korea nuclear weapon. Bloomberg reported that Chinese Foreign Minister Wang Yi told his South Korean counterpart Yun Byung Se by phone on Friday to start negotiations on nuclear arms in North Korea. The start of dialogue with South Korea showed China was really agitated by North Korean's last nuclear test.

North Korea has conducted four nuclear weapon tests - in October 2006, May 2009, February 2013 and last Wednesday. North Korea depends on China as its main trading partner, so provoking China to cooperate with South Korea may not deliver a good result for Pyongyang.