Work was suspended on 14 August, a foreign ministry spokesman is quoted as telling the state news agency KCNA.

North Korea says it took the step because the US failed to remove it from a list of state sponsors of terrorism.

But the US says it wants to agree more stringent verification processes before it does so.

The dispute on the nuclear enrichment programmes of North Korea has been going on for a long time and causing high tension between America and North Korea.