With South Korea set to join the United Nations Security Council in four days, the country could soon take a more active role in getting the international body to punish North Korea for its recent long-range rocket launch, diplomatic sources said Friday.

Starting Jan. 1, South Korea will serve as a non-permanent member of the 15-nation council for two years. The council is the U.N.'s top decision-making body, tasked with maintaining world peace.

Following North Korea's Dec. 12 rocket launch, Seoul has been joined by Washington and other nations in condemning the lift-off as a violation of U.N. resolutions that ban the communist country from testing ballistic missile technology.

It remains unclear, however, whether China, as North Korea's key ally and a veto-wielding council member, will agree to imposing additional sanctions on Pyongyang.

North Korea is already under sanctions for its previous rocket launches and nuclear tests.

"The Chinese mission to the U.N. has not yet received guidelines from the Chinese government," a diplomatic source at the U.N. said, asking that he not be identified. "Even if it were to receive instructions today, it's unclear what their position will be and it usually takes a week to draw up a statement, so it will be difficult to reach a conclusion by the end of the year."

Seoul and Washington are reportedly firm on pushing for additional sanctions.

"In four days, (South Korea) will become an official member of the Security Council, so it will be able to speak up more on issues regarding North Korea and the Korean Peninsula," said another source at the U.N.

The source also pointed out, however, that South Korea's membership on its own may not spur the decision-making process. "In order to heighten pressure on the North, timing is just as important as the form (of action taken), and one could argue too much time has already passed."

(Yonhap News)