U.S., China were reacting to nuclear weapons threats.
BEIJING - The United States and China reacted sharply to the latest belligerent language from North Korea, which called the United States its "archenemy" and said it planned to conduct another nuclear weapons test despite international sanctions.
China called for renewed negotiations with Pyongyang, while the United States promised "additional steps" beyond the expanded sanctions adopted by the United Nations earlier in the week. The sanctions notably had the support of Beijing, suggesting growing frustration with its longtime ally.
South Korea's new president will not tolerate North Korean provocations but will continue to push for dialogue with Pyongyang, a special envoy to President-elect Park Geun-hye said hours after the North's declarations. Park, who takes office next month, said Seoul will continue to provide food and medical aid as part of a "trust-building" policy for the two Koreas.
The two superpowers were reacting to a tirade issued on Thursday by North Korea's National Defense Commission that was provocative even by Pyongyang's standards.
Calling the United States the "archenemy of the Korean people," the commission went on to say: "We are not disguising the fact that the various satellites and long-range rockets that we will fire and the high-level nuclear test we will carry out are targeted at the United States."
North Korea's confrontational stand dampened hopes that the country might be following a more moderate course under its new leader, Kim Jong Un, 30, who took over 13 months ago after the death of his father, Kim Jong Il.
In Washington, White House spokesman Jay Carney called the remarks from Pyongyang "needlessly provocative."
Carney said the recent Security Council resolution freezing assets and banning travel by North Korean officials should send a "strong message of the international community's opposition to North Korea's provocations."
Defense Secretary Leon Panetta said the United States is "very concerned" about North Korea's threats and "fully prepared ... to deal with any kind of provocation."
On Thursday, Xi Jinping, the new head of the Chinese Communist Party, was quoted in major Chinese state newspapers recommending the resumption of six-nation talks that collapsed four years ago to address the North Korean nuclear program.
Impoverished but heavily armed North Korea already has conducted two nuclear tests, in 2006 and 2009.
Analysts generally believe that North Korea is still many years away from a workable weapon that could reach the United States.
The Associated Press contributed to this report.