Leaving North Korea's nuclear program increasingly isolated from international scrutiny, two U.N. nuclear inspectors expelled by the communist country arrived in China early Tuesday.
The two inspectors -- believed to be a Lebanese man and a Chinese woman -- emerged from the arrival hall at Beijing's Capital Airport on a flight from Pyongyang.
"We cannot comment on anything at this stage," the man said, mobbed by reporters.
The inspectors said they would head to the International Atomic Energy Agency's headquarters in Vienna as soon as possible.
North Korea ordered the expulsion of the two U.N. monitors on Friday, depriving the U.N. atomic agency of its final means of monitoring a nuclear program Washington fears will be used to produce atomic weapons.
On Monday, Russia, North Korea's longtime ally, warned the communist regime not to withdraw from an international agreement to halt the spread of nuclear weapons.
Russia's comments were a blow to the North's efforts to cast the nuclear issue as a dispute strictly with the United States.
South Korea expressed alarm at signs its neighbor was preparing to exit the treaty, which seeks to confine nuclear weapons to the United States, Russia, Britain, France and China. Still, the South insisted dialogue was the only way to resolve the problem peacefully.
South Korean President-elect Roh Moo-hyun requested that the United States consult South Korea, a close ally, before formulating a new approach in its North Korea policy.
"Success or failure of a U.S. policy toward North Korea isn't too big a deal to the American people, but it is a life-or-death matter for South Koreans," he told reporters Tuesday. "Therefore, any U.S. move should fully consider South Korea's opinion."
Washington rules out any talks before the North changes course. Assistant Secretary of State James Kelly will go to South Korea next month to talk to U.S. allies -- but not to North Korea "at this time," Secretary of State Colin Powell said Sunday.
The Bush administration said Monday that North Korea is dangerously isolating itself from the world community, including China, by its declared determination to revive its nuclear weapons program.
"The international community has made clear that North Korea's relations with the outside world hinge on its termination of its nuclear programs," deputy White House spokesman Scott McClellan told reporters covering President's Bush's holiday respite at his Texas ranch.
The diplomatic flurry followed Pyongyang's hints in a statement Sunday that it might abandon the Treaty on the Nonproliferation of Nuclear Weapons, a move that would deepen the crisis over the isolated country's decision to restart its nuclear facilities and expel U.N. nuclear inspectors.
Withdrawing from the pact means the impoverished North is intent on raising pressure on the United States to negotiate over energy sources -- and is prepared to turn its back on its international obligations to do so. Yet leaving the pact could be a largely symbolic gesture, as U.S. officials believe North Korea already has one or two nuclear bombs.
In recent weeks, the North cut U.N. seals and impeded surveillance equipment at a nuclear reactor in Yongbyon and its spent fuel pond, a fuel fabrication plant and a reprocessing facility. North Korea had agreed to freeze the facilities under a 1994 deal with the United States in exchange for energy supplies.
Pyongyang said earlier this month it planned to reactivate the facilities to produce electricity because Washington had halted promised energy sources. The embargo was put in place after North Korea admitted in October to covertly developing nuclear weapons using enriched uranium, in violation of the agreement.
After Washington warned it away from reviving the Yongbyon plant, North Korea said U.S. policy was leading the region to the "brink of nuclear war."
In Moscow, Mikhail Lysenko, the director of the Foreign Ministry's security and disarmament department, also warned Pyongyang against withdrawing from the treaty. He said Russia supports the 1994 agreement and insists on a "constructive dialogue" among all involved, and that Moscow was consulting with both Koreas, the United States, Japan and China.
Outgoing South Korean President Kim Dae-jung, who won the Nobel Peace Prize in 2000 for his efforts to reconcile with the North, vowed Monday to continue his "sunshine" policy of engaging North Korea. Critics say this policy gives North Korea too much in return for little.
But President-elect Roh, who takes office in February, told the military to set up a contingency plan in case the United States reduces the strength of its 37,000 troops stationed in South Korea as a deterrent against the North.
There are no confirmed U.S. plans for a withdrawal. But Seoul worries that if the United States reduces its forces -- reacting to anti-U.S. sentiment among South Koreans -- the South would be more vulnerable to an attack from the North.
The nonproliferation treaty was adopted in 1968 and ratified by 187 countries, though not by at least three countries known to possess nuclear weapons -- India, Pakistan and Israel. North Korea signed the treaty in 1985 but tried to withdraw in 1993 over suspicions it was producing weapons. That crisis was averted by the 1994 energy deal with the United States.
The North's foreign news outlet, KCNA, said anti-U.S. "mass" rallies were held in two North Korean cities -- Wonsan and Hamhung -- on Monday.
"If the U.S. imperialists finally ignite a war of aggression while threatening the (North) Korean people with force ..., only corpses and death will await the aggressors," KCNA quoted a speaker as saying.
The Associated Press contributed to this report.