Iran has announced its plans to upgrade uranium enrichment centrifuges at Natanz plant to the UN nuclear agency, reports citing diplomats say.

The move would allow the country to refine uranium at a faster rate, increasing fears among western states about Iran’s intentions.

Iran insists its nuclear programme is peaceful in purpose. The US and its allies fear it seeks nuclear weapons.

The plan was set out in a letter to the IAEA dated January 23, reports said.

The letter is said to mention a model of centrifuge, called IR2m, which can enrich two or three times faster than the present equipment being used by Tehran, according to the Associated Press.

Iran has announced its plans to upgrade uranium enrichment centrifuges at Natanz plant to the UN nuclear agency

The International Atomic Energy Agency sent a letter to member states saying Iran had informed the agency of its plans to use the improved machines at its fuel enrichment plant in Natanz, according to a document seen by Reuters.

“The Secretariat of the Agency received a letter from the Atomic Energy Organization of Iran [AEOI] dated 23 January 2013 informing the Agency that <<centrifuge machines type IR2m will be used in Unit A-22>> at the Fuel Enrichment Plant [FEP] at Natanz,” the IAEA communication is reported to say.

The Natanz facility, in central Iran, is at the heart of the country’s dispute with the United Nations Security Council.

Meanwhile, on Thursday, the European Union’s top foreign policy official said she believed that negotiations on the country’s nuclear programme would resume shortly.