The U.N. Security Council adopted a resolution Thursday targeting North Korean finances in response to Pyongyang's nuclear test in February.
North Korea responded Friday with more threats to abandon its non-aggression measures with South Korea after warning it may carry out pre-emptive nuclear strikes in response to increased sanctions pressure.
Kim Min-seok, a spokesman for the South Korean Defense Ministry, said Pyongyang would regret taking any action against South Korea.
"If North Korea attacks South Korea with a nuclear weapon, Kim Jong Un's regime will perish from the Earth," he was quoted by the Yonhap news agency as saying from Seoul.
The United States and China presented a draft of the resolution this week on the North Korea threat. Chinese Foreign Ministry spokesman Qin Gang said, following the vote Thursday, the resolution sent a "necessary and moderate" response to North Korea.
The resolution calls on Pyongyang to abandon its nuclear weapons program and urges the government to not conduct further nuclear tests.
"Overall, it is balanced," the Chinese spokesman was quoted by the official Xinhua news agency as saying.