Satellite images of activity at North Korea's main nuclear complex support Pyongyang's claims it is constructing an experimental light water reactor in defiance of global pressure to denuclearise, a US think tank says.
South Korean foreign minister Kim Sung-hwan said that by building such a reactor, the North was violating UN resolutions banning the secretive state from any nuclear activity.
Analysts say the construction of the new reactor, along with reports of activity at a nuclear test site which have fuelled speculation of a third atomic test, could be used as leverage by the North at the negotiating table.
North Korea has said it wants to return to stalled aid-for-disarmament talks, but both Seoul and Washington have dismissed its pledges to denuclearise as insincere.
Even though it has exploded nuclear devices, North Korea has not shown it has a working nuclear bomb.
North Korea has tried to secure a light-water reactor for a number of years, claiming such a project would be for peaceful energy purposes. The type of reactor is considered relatively proliferation-resistant, meaning it is unlikely to be diverted for an arms programme.
Analysts are sceptical of North Korea's ability to build a light-water reactor indigenously, because it requires key components that only advanced nuclear states such as the United States can provide.
The Institute for Science and International Security (ISIS) reported that images taken on November 4th showed the frame of a large building under construction at the Yongbyong site, saying this backed reports by experts that the North was building a reactor.
Reuters