International monitors arrived in Beijing today on their way to North Korea to keep watch over the nuclear complex at the heart of a disarmament deal.
The six experts from the UN International Atomic Energy Agency (IAEA) are due to fly to North Korea tomorrow to take the place of colleagues at the Yongbyon complex, which can make plutonium that can be used in weapons.
Their arrival was another step in a February disarmament pact offering heavy fuel oil in return for freezing and ultimately disabling Yongbyon.
North Korea halted its antiquated reactor and plant that turns used uranium fuel into arms-grade plutonium earlier this month after the first batches of fuel oil arrived. It also invited IAEA personnel back into the country.
North Korea agreed at six-party talks in February to close Yongbyon, about 100 kilometres north of Pyongyang.
The next step of deal among the two Koreas, China, Japan, Russia and the United States calls on Pyongyang to "disable" its nuclear facilities and provide a full accounting of its nuclear weapons programmes.
Talks between the countries this month failed to yield a deadline for those steps.