Angered by recent tensions and 'hostile policies' directed at them, North Korea announced Saturday it is considering ending its self-imposed 1999 moratorium on ballistic missile tests should the United States not take steps to improve strained relations.
Also on Saturday, Reuters news service reported that a North Korean diplomat claimed the controversial Yongbyon nuclear reactor, focus of spiraling tensions with the United States, would operable in a few weeks' time.
Son Mun San, counselor for relations with the Vienna-based International Atomic Energy Agency, said the reactor will be ready "to start in a few weeks, not a few months."
And as numerous nations stepped up to condemn North Korea's withdrawal from the Nuclear Nonproliferation Treaty on Friday, Pyongyang assumed a defiant stance, declaring itself ready to "mercilessly wipe out" nations that infringe upon its sovereignty.
North Korea stopped long-range missile testing in September 1999, one year after test-launching a missile that sailed over Japan, landing in the Pacific Ocean. The moratorium was supposed to last through 2004.
"Because all agreements have been nullified by the United States side, we believe we cannot go along with the self-imposed missile moratorium any longer," Choe Jin Su, the North's ambassador to Beijing announced at a news conference.
Choe also accused Washington of failing to respond positively to the 1999 moratorium, which was intended as a good-will gesture toward opening talks on normalizing relations.
On Saturday, a newspaper commentary carried by the state news agency KCNA warned: "If any forces attempt to encroach upon the sovereignty and dignity of the DPRK[Democratic People's Republic of Korea] it will mercilessly wipe out the aggressors and mete out stern punishment to them."
Public sentiment on both sides of the Korean border was flaring Saturday, with large rallies in the South and North Korean capitals.
In Seoul, about 30,000 people turned out to support the U.S. military presence here. But in the North, state media reported that more than a million people flooded the streets to praise the communist government's decision Friday. (The report could not be confirmed, because the North severely restricts access by foreign journalists.)
Speakers at the Pyongyang rally backed the government withdrawal from the nuclear treaty as "a legitimate measure for self-defense," according to KCNA.
"The participants are fully determined to use every means and method and fight a life-and-death battle against those who try to infringe upon the nation's sovereignty and right to existence without any slightest compromise and concession," it added.
Meanwhile, the world was rushing to find a diplomatic solution.
Russia's nuclear energy minister suggested Saturday that Moscow build a nuclear power station in North Korea to help defuse the crisis. Russia could assist North Korea with its nuclear energy program to help bring the country back into the framework of the Nuclear Nonproliferation Treaty, Alexander Rumyantsev said.
Meanwhile, the global outcry against the North spread, with the European Union expressing "grave concern."
Australian Defense Minister Robert Hill said it was "foolish" for the impoverished nation to break a deal with the United States that guaranteed it energy and food aid in exchange for freezing its nuclear weapons program.
"They've unilaterally walked away from that deal presuming that they can obtain some further economic advantages through doing so. It's a foolish thing to do," Hills said.
In Seoul, visiting French Foreign Minister Dominique de Villepin said the issue should be dealt with by the U.N. Security Council.
Going to the Security Council raises the possibility of sanctions against North Korea. North Korea said Friday that sanctions would be tantamount to "a declaration of war."
North Korea is believed to have missiles that can reach any part of South Korea and most of Japan. U.S. officials say North Korea is developing ballistic missiles that can reach Alaska and Hawaii with a payload of several hundred pounds.
North Korea has cited "U.S. vicious, hostile policy" and an alleged "nuclear threat from the United States side" for its decision to immediately pull out of the 1968 Nuclear Nonproliferation Treaty, a cornerstone of international efforts to prevent the spread of nuclear weapons.
On Saturday, KCNA commentary also condemned the United States for the seizure of a North Korean ship carrying missiles to Yemen last month, and said it was "intended to more wantonly infringe upon the sovereignty of an independent state."
Choe Jin Su rejected international criticism of his country's missile exports, saying they were "entirely within our sovereignty." Such exports are a main source of hard currency for the North Korea.
In December U.S. and Spanish warships seized the North Korean ship carrying Scud missiles in the Arabian Sea. They later allowed it to sail after receiving assurances the Scuds would not be transferred elsewhere in the tense Persian Gulf region.
U.S. Secretary of State Colin Powell renewed the Bush administration's overture to hold direct talks with North Korea but said the United States "will not enter any kind of talk or dialogue where North Korea is given any impression but that they have to come into compliance."
Meanwhile, two North Korean envoys were to meet for a second day Saturday in Santa Fe, New Mexico, with New Mexico Gov. Bill Richardson, a former U.N. ambassador and veteran diplomatic troubleshooter.
Mohamed ElBaradei, director general of the U.N. nuclear agency, said the Security Council should intervene unless North Korea reverses its actions within a few weeks.
Earlier, Washington had said North Korea already was violating the global treaty by secretly pursuing weapons development and flouting U.N. safeguards. The United States believes the North already has one or two nuclear bombs.
The crisis worsened last month when Pyongyang expelled U.N. inspectors and said it was reactivating a nuclear reactor in Yongbyon to generate much-needed electricity.
Experts say the reactor generates little power, and that the North could make several more bombs in six months if it extracts weapons-grade plutonium from spent fuel rods.
The Associated Press contributed to this report.