The move was meant to be North Korea's first step toward giving up its nuclear weapons program in return for energy aid and better relations with the United States.
But Pyongyang has so far refused to close and seal its Yongbyon reactor until it gets back $25 million frozen at a Macau bank.
North Korea said on April 13 it would soon check if it can access the money that the United States says has been unblocked.
The history of negotiations with North Korea has been tortuous and full of setbacks.
Back in 1994, North Korea made a deal with the United States under which it promised to shut down its nuclear reactor, which could be used to produce weapons-grade plutonium, in exchange for a civilian light-water reactor and economic aid from Washington.
But in 2002, Pyongyang announced it had resumed its nuclear program. It subsequently expelled IAEA inspectors from the country and said it had managed to produce a nuclear weapon.
(compiled from agency reports)
The Proliferation Threat
The Arak heavy-water plant in central Iran (Fars)
BENDING THE RULES. Henry Sokolski, executive director of the Nonproliferation Policy Education Center, told an RFE/RL-Radio Free Asia briefing on January 9 that the West is hamstrung in dealing with Iran and North Korea because of the way it has interpreted the international nonproliferation regime to benefit friendly countries like India and Japan.
LISTENListen to the entire briefing (about 90 minutes):
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