The United States and South Korea have condemned reports from North Korea concerning the country's nuclear programme.
Officials in Pyongyang say North Korea has successfully removed fuel rods from a nuclear reactor at Yongbyon.
The rods can be treated to produce plutonium, possibly enough for two nuclear weapons.
US State Department spokesman Richard Boucher said the move was a step in the wrong direction and he urged North Korea to re-enter talks on the nuclear issue.
