NEW YORK/SEOUL (Yonhap News) ― South Korea could take a more active role in getting the United Nations Security Council to punish North Korea for its recent long-range rocket launch, diplomatic sources said Friday.

South Korea is set to serve as a non-permanent member of the 15-nation Council for two years, beginning Jan. 1. The Council is the U.N.’s top decision-making body that can tighten sanctions on North Korea.

Seoul, Washington and other nations condemned North Korea’s Dec. 12 rocket launch 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.

South Korea will soon be able to speak up more on North Korea as it will become an official member of the Security Council, though its membership on its own may not spur the decision-making process, said another source at the U.N.

“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,” the source said.

There are concerns that North Korea may respond to any additional U.N. sanctions with another nuclear test.

North Korea carried out its first and second nuclear tests in 2006 and 2009, weeks after the U.N. Security Council adopted a resolution and condemned Pyongyang for its long-range rocket launches.

In Washington, a U.S. think tank said North Korea appears ready to conduct a nuclear test in as little as two weeks after a political decision is made to move forward.

“Satellite photos as recent as December 13 show that Pyongyang is determined to maintain a state of readiness at the area of the Punggye-ri nuclear test site, where a third test is expected even in the dead of winter,” the U.S.-Korea Institute at the Johns Hopkins School of Advanced International Studies said on its Web site, 38 North.

Won Sei-hun, head of South Korea’s National Intelligence Service, also told lawmakers earlier this month that the North is prepared to test-blast a nuclear device at any time, according to Rep. Chung Moon-hun of the ruling Saenuri Party.

On Saturday, North Korea renewed its determination to carry on launching rockets loaded with satellites.

“Our satellite launches are an exercising of sovereignty that is in full compliance with the treaty on space, which stipulates that the peaceful use of space is a right of all countries,” the North’s main newspaper, Rodong Shinmun, said in a report.