Beijing/Kuala Lumpur: The UN nuclear watchdog said on Wednesday that North Korea had closed all five of its major nuclear facilities, a milestone in efforts to get the country to give up its nuclear weapons programmes.

The announcement came as negotiators at six-party talks on North Korea's nuclear weapons programme sat down to talks in Beijing where the United States held out hope of agreeing to a disarmament schedule over the next two days.

"Yes, we now verify that all the five nuclear facilities have been shut down," Mohamed ElBaradei, the chief of the International Atomic Energy Agency, told reporters in the Malaysian capital, referring to the Yongbyon reactor complex.

The reactor produces material that can be turned into weapons-grade plutonium and in February North Korea agreed to close it in return for 50,000 tonnes of heavy fuel oil, which began moving there from South Korea last week.

Asked if Yongbyon had been left in a condition that would allow IAEA officials determine how much plutonium was produced there, ElBaradei said:

"What we've done yesterday is complete the shutdown of the facilities. We still have a long way to go. We still have to work with the North Koreans about the history of production in these facilities, but that will be part of North Korea providing us with inventory of nuclear materials. So it's a very long and complex process."

North and South Korea, the United States, China, Japan and Russia will now start to explore how to permanently scrap Yongbyon.

US envoy Christopher Hill said there was much work to be done at Wednesday's talks but held out hope of agreeing to a disarmament timetable.