Beijing ? Two U.N. nuclear inspectors expelled by North Korea arrived in China early today, leaving the communist nation’s nuclear program increasingly isolated from international scrutiny.

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 and said they would head to the International Atomic Energy Agency’s headquarters in Vienna as soon as possible.

“We cannot comment on anything at this stage,” the man said, mobbed by reporters.

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.

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.

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 a 1994 energy deal with the United States.

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.