U.S. Secretary of State John Kerry is expected to push China to take more action to address North Korea’s recent nuclear test and try to ease tensions around Beijing’s claim on the South China Sea, the Wall Street Journal reported Sunday. Kerry arrived in Laos Sunday to kick off a three-day visit to Asia, during which he will go to Cambodia on Monday and then travel to Beijing to meet with Chinese President Xi Jinping, Foreign Minister Wang Yi and other officials.

World leaders have been discussing new sanctions against North Korea after it announced it had tested a nuclear bomb earlier this month, and Kerry will emphasize the need for China to join in creating a united front against the totalitarian country, a State Department official traveling with Kerry told the Wall Street Journal. The secretary of state will also remind China that, as North Korea’s main ally and close neighbor, other countries are counting on it to take its own stand as well.

It is important to “cut off avenues of proliferation and retard North Korea's ability to gain the wherewithal to advance its nuclear and its missile programs,” the State Department official said.

North Korea relies heavily on China for conducting business with the global community, and gets nearly all of its oil from Beijing, so strong action from China would send a significant message to Pyongyang.

While China has said the U.S. made the situation in North Korea worse, Kerry holds a different view. He said earlier this month that the nuclear test showed China’s method of working with North Korea is not sustainable.

“The fact that despite China’s friendly overtures to the DPRK, Kim Jong Un turned around and did the thing that he knew the Chinese most objected to — a nuclear test — certainly tells me that that message hasn’t yet gotten through,” the State Department official said.

Before he meets with leaders in Beijing, Kerry will address the Association of Southeast Asian Nations in Laos, telling the 10 member nations to band together in dealing with disputes over the South China Sea. Over the past few months, China has built artificial islands suitable for use as military bases in the sea. This has caused alarm among the U.S. and other nations that have claims to the area, so Kerry will try to mediate some of these issues during his visit.