South Korea's chief nuclear envoy pressed China on Thursday to play an "important role" in imposing tougher sanctions against North Korea following its latest nuclear test last week, saying Pyongyang should pay a "significant price" for the act.

Hwang Joon-kook, Seoul's chief envoy on North Korea's nuclear issue, made the remarks upon his arrival at the Beijing airport, ahead of talks with his Chinese counterpart, Wu Dawei, later in the day. 

China, a key ally of North Korea, has expressed public displeasure over the North's nuclear program for years but is again reluctant to join the international community in slapping tougher sanctions on Pyongyang. 

"About 90 percent of North Korea's trade relies on China," Hwang said. "I think that China could and should play an important role." 

The six-nation talks on North Korea's nuclear program, which involve South Korea, North Korea, the United States, China, Russia and Japan, have been stalled since late 2008. 

North Korea announced on Jan. 6 that it successfully detonated a hydrogen bomb that marked the North's fourth nuclear test since 2006. 

On Wednesday, South Korean President Park Geun-hye called on China to take "necessary" actions in punishing North Korea for its latest nuclear test with the strongest international sanctions. 

Hwang and his counterparts from the U.S. and Japan held three-way talks in Seoul on Wednesday, and they agreed on new "meaningful" sanctions on North Korea that should be approved by the U.N. Security Council. 

"Under the current situation where North Korea conducted a nuclear test, the five nations, including China, must ensure cooperation and coordination to make North Korea pay a significant price," Hwang said. 

The role of China, which keeps North Korea's moribund economy afloat, is important in ensuring the effectiveness of tougher sanctions against the isolated North.

However, many analysts believe that China's Communist Party leadership won't exert enough leverage on North Korea because a sudden collapse of the North's regime could threaten China's own security interests. (Yonhap)