It has been confirmed that an unofficial delegation from the United States is to visit North Korea to tour a controversial nuclear complex at Yongbyon.
The group will include congressional staffers and a former top scientist at a US nuclear laboratory.
The US administration has said it is not involved in the visit scheduled for next week.
It will be the first time that the facility, which is thought to have been producing nuclear weapons, has been inspected by foreigners since United Nations personnel were expelled from the communist state 12 months ago.
There is international pressure on the Pyongyang government to abandon its nuclear programme in exchange for aid and better ties with the West.