SEOUL, South Korea (CBS) North Korea's top military body warned Thursday that the regime is poised to conduct a nuclear test in response to U.N. punishment, and made clear that its long-range rockets are designed to carry not only satellites but also warheads aimed at striking the United States.
The National Defense Commission rejected Tuesday's U.N. Security Council resolution condemning North Korea's long-range rocket launch in December as a banned missile activity and expanding sanctions against the regime. The commission reaffirmed in its declaration that the launch was a peaceful bid to send a satellite into space, but also said the country's rocket launches have a military purpose: to strike and attack the United States.
The commission pledged to keep launching satellites and rockets and to conduct a "high-level" nuclear test as part of defensive measures against the U.S.
"The various satellites and long-range rockets that we will fire as well as the high-level nuclear test that we will carry out, we are not hiding the fact that it is targeted towards United States, our worst enemy," the commission said.
"Settling accounts with the U.S. needs to be done with force, not with words, as it regards jungle law as the rule of its survival," the commission said.
The U.S. State Department had no immediate response to Thursday's statement. On Wednesday, after Pyongyang's foreign ministry issued its own angry response to the Security Council decision and said the North would bolster its "nuclear deterrence," U.S. envoy to North Korea Glyn Davies urged restraint.
"It is important that they heed the voice of the international community," Davies said Wednesday in South Korea. He was meeting with government officials on a trip that also will take him to China and Japan to discuss how to move forward on North Korea relations.
Davies said that if North Korea begins "to take concrete steps to indicate their interest in returning to diplomacy, they may find in their negotiating partners willing partners in that process."
CBS News' Shannon Van Sant says reaction from North Korea's longtime ally China in the wake of threats was predictably muted. China's Foreign Ministry urged all parties "to remain calm," and called for a resumption of the long-stalled six-party talks.
While China could play a key role in pressuring the North to give up its efforts for a nuclear weapon, it is unlikely to do so, says Van Sant. China is keen to avoid instability and any influx of refugees along its northeastern border. Beijing also has significant trade ties with Pyongyang, and would be reluctant to endanger that relationship.
North Korea carried out underground nuclear tests in 2006 and 2009, both times just weeks after receiving U.N. sanctions for launching long-range rockets it claimed were peaceful bids to send satellites into space.
At a military parade last April, North Korea showed off what appeared to be an intercontinental ballistic missile.
Experts say the North Koreans must conduct further tests of its atomic devices and make them smaller before they can be mounted as nuclear warheads onto long-range missiles.
Though it insists its efforts to launch a satellite are peaceful, North Korea also claims the right to build nuclear weapons as a defense against the United States, which stations more than 28,000 troops in South Korea. The adversaries fought in the three-year Korean War, which ended in a truce in 1953 and left the Korean Peninsula divided by the world's most heavily fortified demilitarized zone.
North Korea has enough weaponized plutonium for about four to eight bombs, according to nuclear scientist Siegfried Hecker, who visited North Korea's nuclear complex in 2010. In 2009, Pyongyang also declared that it would begin enriching uranium, which would give North Korea a second way to make atomic weapons.
© 2013 CBS Interactive Inc. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.