By Mark Heinrich and Sylvia Westall
Vienna - North Korea had expelled United Nations monitors from its plutonium-making nuclear plant and planned to start reactivating it next week, officials said on Wednesday, as the country backtracked on a 2007 deal for it to scrap its atomic bomb programme.
The communist state said on Friday it was working to restart the Yongbyon atomic complex that it had been dismantling since November 2007 under a disarmament-for-aid agreement with five powers.
Olli Heinonen, the International Atomic Energy Agency's head of non-proliferation safeguards, told a closed meeting of the IAEA's 35-nation board of governors that monitors were forced to leave the plutonium facility this week.
"(North Korea) also in-formed IAEA inspectors that they plan to introduce nuclear material to the reprocessing plant in one week's time," IAEA spokesperson Melissa Fleming told reporters outside the Vienna meeting.
Gregory Schulte, the United States ambassador to the IAEA, said North Korean moves to halt and reverse disablement were "unsettling".
Western diplomats and nuclear analysts have said North Korea would need at least several months to bring the largely broken up installation back on line.
Diplomats close to the IAEA said the three monitors ousted from positions at the plutonium facility were still observing other parts of the Soviet-designed Yongbyon complex.
North Korea's foreign ministry has said steps were under way to restore Yongbyon to its "original state" - reneging on a February 2007 accord to scrap its nuclear arms programme to obtain sweeping trade and diplomatic benefits.
Last month, North Korea said it planned to restart Yongbyon because it was angry at Washington for not taking it off its terrorism blacklist. Earlier in September, it made minor but initial moves to restart the plant, US officials said.
Washington has said it would duellist Pyongyang once it allowed inspectors to verify claims it made about nuclear arms output. Pyongyang wants a more flexible verification mechanism, analysts said.
Before Yongbyon's shutdown, US officials estimated North Korea had produced about 50kg of plutonium, enough for six to eight nuclear weapons.