"We have now reached an understanding on how we are going to monitor the sealing and shutting down of the Yongbyon nuclear facility," the head of the International Atomic Energy Agency (IAEA) team, Olli Heinonen, told reporters.

However, Heinonen said it was still too early to say when the Yongbyon reactor, which is at the core of North Korea's nuclear weapons programme, would be sealed.

Heinonen was speaking to reporters at Beijing airport after he and the three other members of the IAEA inspection team flew in from Pyongyang, ending a five-day visit to North Korea.

The team was the first IAEA group to visit North Korea since the UN nuclear watchdog was kicked out of the country in 2002.