The U.S. State Department said Monday any moves by North Korea to reprocess spent nuclear fuel or to test a nuclear device would have serious international consequences for Pyongyang. The remarks came as Pentagon officials reported what they called a "hostile" incident involving a U.S. reconnaissance plane and North Korean fighter jets Sunday over the sea of Japan.
In another sign of rising tensions with Pyongyang, the Pentagon said four North Korean fighters intercepted the U.S. Air Force RC-135 reconnaissance plane in international waters over the Sea of Japan and shadowed the U.S. plane for about 20 minutes.
The Sunday incident, which occurred some 240 kilometers off the North Korean coast, included an approach by a North Korean plane within 20 meters and U.S. officials said one of the fighters engaged its fire control radar, locking on the American aircraft.
The U.S. plane returned to its base in Japan without damage, though Pentagon sources called the incident hostile and said it brought to mind a 1969 episode in which a U.S. surveillance plane was shot down, claiming 31 American lives.
The airborne encounter comes amid heightened tensions between the United States fueled by a succession of steps by North Korea shelving international accords and restarting its nuclear program.
The New York Times reported Saturday that officials have told President Bush they believe North Korea may soon begin reprocessing spent fuel rods at its newly re-opened Yongbyon nuclear complex, a move that could give it the capacity to produce several nuclear weapons.
At a briefing here, State Department spokesman Richard Boucher said reprocessing or testing a nuclear device would increase North Korea's isolation from the international community.
"Any moves by North Korea to either reprocess spent fuel or conduct a nuclear test would be a matter of serious concern to the entire international community. All of North Korea's neighbors have made clear that this kind of development would be unwelcome and have serious consequences for them," Mr. Boucher said.
Mr. Boucher reiterated the United States wants a "peaceful and diplomatic solution" to the situation created by North Korea's nuclear moves, and is continuing to work closely on the issue with, among others, South Korea, China, Russia, the European Union and the International Atomic Energy Agency.