"Some countries are angry that our people defend their nuclear rights,'' foreign ministry spokesman Ramin Mehmanparast said today.
When Western powers "want to pressure us they craft such scenarios which is unacceptable,'' he said.
He was reacting to a report in the British newspaper The Times which said yesterday it had obtained notes describing a four-year plan by Iran to test a neutron initiator, the component of a nuclear bomb which triggers an explosion.
The Times claimed that foreign intelligence agencies dated the documents to early 2007 - four years after Tehran was thought to have suspended its weapons program.
It said the documents detailed a plan to test whether the device works - without leaving traces of uranium that the outside world could detect.
Its uranium enrichment work is at the centre of fears about the program as the process which makes nuclear fuel can also be used to make the fissile core of an atom bomb.
Iran is under three sets of UN sanctions for its refusal to suspend enrichment and risks a further round after rejecting a UN-brokered deal to send its low enriched uranium abroad to be further refined into fuel for a research reactor.