Iran on Monday resumed work in uranium conversion facilities in the central city of Isfahan shortly after UN nuclear watchdog inspectors finished installing surveillance equipment there, state television said.

"Iran resumed the uranium conversion work in Isfahan, and the inspectors of the International Atomic Energy Agency (IAEA) finished installing surveillance equipment," the report said.

Meanwhile, a formal reply to the European Union (EU) on its comprehensive proposal on the Iranian nuclear standoff was also turned over.

Foreign Ministry spokesman Hamid-Reza Asefi said on Monday that Iran had officially informed ambassadors of the European trio of Britain, France and Germany that the EU proposal was "not acceptable" to Tehran.

"Denial of Iran's right to continue uranium enrichment and possession of fuel cycle as well as production of fuel are among the most important reasons for Iran's rejection of the proposal," he said.

He stressed that the EU proposal had pursued a "discriminatory and baseless" standard and failed to touch on objective guarantees of Iran's natural right on peaceful nuclear technology, which ran counter to the Paris Agreement.

On Monday evening, IAEA spokesman Mark Gwozdecky confirmed that Iran had started to "feed uranium ore concentrate into the first part of the process line at the uranium conversion facility at Isfahan."

The UN nuclear watchdog expressed regret that Tehran began the conversion work before the complete testing of the newly installed supervisory equipment, which usually takes 24 hours.

The resumption started almost at the same time as the official IRNA news agency reported that Ali Larijani, the hardline and conservative former broadcast body chief, was to be appointed the new secretary of the Supreme National Security Council, a post in charge of nuclear talks.

Larijani has criticized Iranian nuclear negotiators for "exchanging a pearl for a bonbon" due to their acceptance of a downright suspension of uranium enrichment activities last October.

Tehran had been threatening to resume the conversion work in Isfahan facilities since the end of July when it began to press the EU to present its promised nuclear proposal on time, which the European trio in late May pledged to submit in two months.

The European trio delivered the nuclear proposal last Friday and urged Tehran to accept it and refrain from the sensitive resumption, saying Iran will face a referral of the case to the UN Security Council otherwise.

French Foreign Minister Philippe Douste-Blazy has said that the world will face a "major international crisis" if Iran did not accept the proposal, calling on the international community to keep "firm."

Under a call of the European trio, the IAEA Board of Governors will hold an emergency meeting on Tuesday to discuss Iran's resumption of uranium conversion activities.

Tehran has rejected the scheduled meeting as illegal and said that it was not afraid of the referral.

The United States accuses Iran of developing nuclear weapons secretly, a charge rejected by Tehran.

Source: Xinhua