In his speech, Ahmadinejad said the door to negotiations with the West remains open. "Iran welcomes any suggestion and dialogue to resolve the issues," he said.

In London, the British Foreign Office said Iran should suspend uranium enrichment immediately.

"We are concerned that Iran appears to have confirmed more nuclear enrichment activity" in violation of UN resolutions, the ministry said in a statement.

"We have always made it clear that we are happy for Iran to have a civil nuclear power program, but they have to satisfy the international community that that is what it is seeking to develop.