Seoul  - North Korea said Friday that it had begun work to restart its Yongbyon nuclear reactor because the United States had failed to keep promises it made in nuclear talks.

The reactor, which North Korea shut down last year as part of those talks, can supply plutonium that can be used to make nuclear bombs.

The restart of the reactor at Yongbyon, 100 kilometres north of Pyongyang, was under preparation while work to rebuild the country's nuclear facilities to their original state had been ongoing for some time, the official Korean Central News Agency (KCNA) said.

Pyongyang "suspended the disablement of its nuclear facilities and work has been under way to restore its nuclear facilities in Yongbyon to their original state since some time ago," an unnamed Foreign Ministry official was quoted as saying.

KCNA said the step was a reaction to the US decision not to remove North Korea from its list of state sponsors of terrorism as agreed in disarmament talks earlier this year. The United States has demanded verification measures be implemented to ensure North Korea is complying with its promises to disarm before its name is taken off the terrorism list.

North Korea, annoyed as the US decision, stopped disabling the reactor in late August.

North Korea now neither wishes to be removed from the list nor does it expect such a step, KCNA quoted a Foreign Ministry spokesman as saying.

"It will go its own way," he was quoted as saying.

Foreign Ministry official Hyon Hak Bong said earlier Friday during energy aid talks with South Korea in the border truce village of Panmunjom that Pyongyang was making "thorough preparations" to restore its nuclear facilities.

"You may say we have already started work to restore them," he said, adding that the communist state would soon announce when the reactor would be restarted. His remarks for the first time confirmed earlier reports about the North's intentions to get Yongbyon back online.

South Korea said in early September that North Korea had started to rebuild its previously disabled nuclear facilities.

Hyon accused the United States of not keeping its part of a deal struck in six-nation disarmament talks in November and described as "unacceptable" the US demands for verification measures.

In talks with the United States, China, Russia, Japan and South Korea, the North agreed to disable its nuclear programme in exchange for energy aid and an easing of sanctions.

South Korean Foreign Minister Yung Myung Hwan said in Seoul that it was unclear whether North Korea was seeking to return to the situation before it shut down its reactor or was trying to gain an upper hand in the nuclear talks.

Meanwhile, in Panmunjom, North and South Korean officials discussed the outstanding energy shipments that were promised to Pyongyang in return for concessions in the nuclear talks, including disclosing its nuclear activities.

South Korean negotiator Hwang Joon Kook told the public broadcaster KBS that he expected progress to be made on the verification issue and the energy aid could be completed as planned.

The six-nation nuclear talks have stalled over the verification dispute, and uncertainty over the health of North Korean leader Kim Jong Il, who has not been seen in public for months, has added to the stalemate.

Hyon rejected intelligence reports that Kim was seriously ill as "nonsense."

"Those [reports] are spread by bad people who do not want our country to fare well," he said.

According to South Korea, Kim suffered a stroke last month. (dpa)