Iran has hit back after European criticism of its decision to set up a uranium conversion plant near Isfahan.
Iran has been accused of keeping some of its nuclear activities secret [Photo: Digitalglobe]
UN ambassador Pirooz Hosseini told Reuters news agency the plant was not in breach of Iran's commitment to suspend uranium enrichment.
On Wednesday the UK, Germany and France issued a joint statement saying the plant's creation sent the wrong signal to the international community.
The row comes less than a week after UN inspectors returned to Iran.
Inspections were suspended earlier in March after a dispute with UN watchdog the International Atomic Energy Agency (IAEA).
The IAEA has rebuked Tehran for keeping some of its nuclear activities secret.
The US, meanwhile, says Iran is using its nuclear power programme to develop weapons.
Mr Hosseini told Reuters that he would be discussing criticism of the new plant with British, French and German representatives in the next few days, adding that Iran would keep its promise made to European countries last October about enrichment and inspections.
"[The plant is] a totally separate issue from our commitment to the suspension of uranium enrichment," he said.
The ambassador did not say whether Tehran would be prepared to shut down the plant, the inauguration of which was announced on Saturday.
Iran says the facility will process uranium ore into gas, a step towards enrichment.
The news prompted a strong reaction from the UK Foreign Office.
"This announcement sends the wrong signal about Iranian willingness to implement a suspension of nuclear enrichment-related activities," it said in a statement.
"It will make it more difficult for Iran to re-establish international confidence in her undertakings. Iran must explain her statement and her intentions."
The German Foreign Ministry expressed similar concerns.