Kim Hyung-suk, a spokesman for South Korea's Unification Ministry, said Tuesday that Pyongyang needed to live up to pledges made in 1991 to eliminate nuclear material from the Korean Peninsula.
"The (Seoul) government has continuously attempted to persuade the North to discard nuclear programs and will continue to call for compliance with the joint declaration and statement," he was quoted by South Korean news agency Yonhap as saying.
North Korea carried out an underground nuclear test Feb. 12.
North Korean rocket launches in 2012, 2009 and 2006 coincided with underground nuclear tests. The Feb. 12 test was said to be of a physically smaller device that was more powerful than previous efforts. Johns Hopkins researchers say North Korea doesn't have the technology to install nuclear warheads on intercontinental ballistic missiles.