The chief nuclear envoys of South Korea and China are to meet in Beijing later Thursday as Seoul puts pressure on China to help punish North Korea over its recent nuclear test.

Since the North's fourth nuclear test last week, South Korea has stepped up diplomatic efforts to win international support for a strong U.N. Security Council sanctions resolution.

China has condemned the North's test but maintained its calls for restraint and dialogue in dealing with Pyongyang.

Hwang Joon-kook, South Korea's special representative for Korean Peninsula peace and security affairs, left for Beijing earlier in the day to meet with his Chinese counterpart Wu Dawei.

"China is a permanent member of the Security Council, with the largest influence on North Korea," he told reporters at Incheon International Airport before boarding his plane. "I believe it's the most important country in responding to the current situation."

The talks come a day after President Park Geun-hye publicly urged China to play a "necessary role" in drawing up strong sanctions against the North.

China is believed to be the only country with power over Pyongyang, as it props up the ally's moribund economy. However, Beijing has been reluctant to punish the North too hard apparently because it serves as a buffer against American influence in U.S.-backed South Korea.

Hwang held trilateral talks with his U.S. and Japanese counterparts in Seoul on Wednesday. The three sides agreed to work closely to ensure that the U.N. Security Council adopts a strong resolution against Pyongyang.

On Tuesday, Hwang will fly to Moscow where he will meet with his Russian counterpart Igor Morgulov for further talks on the issue. Russia is also a permanent member of the council and critical in implementing effective sanctions on the North.

South Korea, China, the U.S., Japan and Russia are all members of the six-party talks aimed at dismantling North Korea's weapons program. The actual negotiations have broken down since their last session in late 2008. (Yonhap)