North Korea's threat to restart its plant that makes arms-grade plutonium is feasible, although the task would be a daunting one, analysts said on Wednesday.
On Tuesday the communist state said that because the United States had not kept to its side of a disarmament-for-aid deal it would stop disabling a Soviet-era Yongbyon nuclear complex and was considering getting back into the plutonium business.
Moscow added its voice to the western criticism on Wednesday, with a Foreign Ministry statement expressing "concern and disappointment" at the North Korean plans.
"The North Koreans have mastered the nuclear fuel cycle. They understand the technical aspects of it," said Daniel Pinkston, an analyst with the International Crisis Group in Seoul. "They have the human resources, which is the most important."
Engineers, working since late last year and mostly overseen by U.S. experts, have almost completed disabling the Yongbyon nuclear plant. The aim is to make it impossible to resume operations for at least a year.
The North Koreans' thinking may be: 'We can rebuild it. We can make it better and we have enough nuclear weapons to deter anyone for the one to three years it might take to get this back up and running'," Pinkston said.
The disablement work was done at three facilities -- a plant that produces nuclear fuel, the North's sole operating reactor and a plant that turns spent fuel into plutonium.
The only major remaining step was the discharging of irradiated fuel rods from the reactor. The rods are still in North Korea and contain enough fissile material for one nuclear bomb, proliferation experts said.
They said the North, which conducted its only nuclear test two years ago, has already produced enough plutonium for about six to eight bombs.
he isolated North's latest announcement confirms the belief of some analysts that its communist leaders have no intention of giving up nuclear weapons, a diplomatic trump card that has repeatedly won them concessions in the past.
"North Korea is biding its time, thinking there is no rush for denuclearisation," said Lee Sang-hyun, director of the security studies programme at South Korea's Sejong Institute.
North Korea was angered that the United States has not dropped it from a terrorism blacklist, something Washington said it would do only after Pyongyang accepted inspectors to verify details of its nuclear inventory.
Once removed from its pariah status, experts estimate the North could see its broken economy grow with increased trade and investment.
Bruce Klingner, an Asian affairs expert with the Heritage Foundation, said the North may have seen the Bush administration as eager to make a deal before leaving office.
He added that during the prolonged talks the North has also seen Washington back down when it said it would not compromise.
"What this has meant is the U.S. agreeing to the North Korean demands and kicking the can down the road on any contentious issues," Klingner said by telephone from Washington.
The sputtering talks that started about five years ago are likely to continue because regional powers see them as the best diplomatic method for engaging North Korea, although Pyongyang's recent announcement slammed the brakes on progress for now.
"Just when we thought the six-party talks where dead ... they keep coming back to life," Klingner said of the talks between the two Koreas, China, Japan, Russia and the United States, Reuters reported.