The UN nuclear watchdog has confirmed that North Korea had shut down its nuclear reactor and four related facilities in what is being seen as a major step in efforts to get the country to give up its nuclear weapons programmes.
The announcement by the head of the International Atomic Energy Agency, Mohammed ElBaradei, came as negotiators sat down for the first day of six-party talks in Beijing on North Korea's nuclear weapons programme.
In February, North Korea agreed to close the Yongbyon reactor, which produces material that can be turned into weapons grade plutonium, in return for 50,000 tonnes of heavy fuel oil, which began arriving from South Korea last week.
North and South Korea, the US, China, Japan and Russia will now start to explore how to permanently scrap Yongbyon.
The US hopes agreement on a disarmament schedule can be reached at the talks over the next two days.
