TOKYO -- Officials in Washington, Tokyo and Seoul say a growing body of evidence about a mysterious nuclear complex in North Korea is heightening their concerns that the unpredictable government of President Kim Il Sung may be closer to producing a crude nuclear weapon than anyone thought just a year ago.
The concerns are being driven by North Korea's continued refusal to allow international inspection of the site at Yongbyon, a nuclear complex 60 miles north of Pyongyang that dates back at least two decades.
But a steady trickle of new intelligence information emerging from North Korea, one of the world's most closed Communist countries, suggests that a host of new installations at the site are nearly complete, including a suspected reprocessing plant that could produce hundreds of pounds of weapons-grade plutonium.
And there are hints that other nuclear complexes, perhaps underground, are being built.
While there are conflicting interpretations of the evidence, each new morsel seems to deepen the enigma of Yongbyon and to stir nervousness among U.S. allies in Asia that Washington may again be misjudging critical warning signals, much as it did with President Saddam Hussein's bomb project in Iraq.
"The Iraqi experience scared us all, and we know much less about North Korea," said a senior Japanese official who has directed Tokyo's efforts to gather intelligence about North Korea's nuclear capabilities. "And it is far more serious to Japan than to the U.S. You have nuclear weapons; we don't."
Interviews with nuclear experts and government officials in Seoul, Tokyo and Washington -- along with new commercially available satellite photographs and sketchy information from recent defectors -- indicate that North Korea has an impressive degree of nuclear expertise.
Although largely cut off from the Western technology and training that brought wealth to many of North Korea's neighbors, Mr. Kim's government has successfully replicated a British reactor used to produce fuel for weapons, obtained some crucial materials from Germany and received tutoring in nuclear physics from the Soviets that continued at least through this summer.
Oratory surrounding the plant is rapidly growing more belligerent. A white paper issued by the South Korean Defense Ministry 10 days ago said that the project "must be stopped at any cost."
Friday, South Korean President Roh Tae Woo pledged for the first time that his nation would not "manufacture, possess, store, deploy or use nuclear weapons," which seemed to confirm that all U.S. nuclear arms there would be removed.
But he also said, "Nuclear weapons in North Korean hands would so dangerous and destabilizing that they would not only threaten the very survival of our nation but could in an instant shatter the peace in Northeast Asia and the world."
Yesterday, North Korea ignored the South's proposal for a nuclear-free peninsula, instead demanding the withdrawal of U.S. troops and nuclear weapons from South Korea.
"The danger of war cannot be removed from the Korean peninsula while the United States is keeping its aggression forces in South Korea," said Rodong Shinmun, an official Communist Party newspaper.