U.S. Deputy Secretary of State Antony Blinken is in Beijing on Thursday for talks with senior Chinese officials as Washington pressed Beijing to join in drawing up tougher U.N. sanctions against North Korea following the North's fourth nuclear test.

Blinken, the second-ranking American diplomat after Secretary of State John Kerry, has met with South Korean and Japanese officials this week and called on China to play a "special role" in punishing North Korea for its latest nuclear test.

"We believe that China has a special role to play, given the special relationship that it has with North Korea," Blinken told reporters in Seoul on Wednesday.

"It has more influence and more leverage over North Korea than any other country because virtually all of North Korea's trade goes to, from or through China," Blinken said. "We are looking to China to show leadership on this issue."

All eyes are on the role of China, which keeps North Korea's moribund economy afloat, after Pyongyang announced on Jan. 6 that it conducted a "successful" test of a hydrogen bomb that marked the isolated regime's fourth nuclear test since 2006.

The latest nuclear test is seen as a diplomatic failure by Chinese President Xi Jinping in trying to rein in the key ally.

While China has said it is "firmly opposed" to the nuclear test, Beijing's leadership has been reluctant to use more leverage over Pyongyang because it could lead to the North's collapse and instability at its border. (Yonhap)