Iran said it would restart some sensitive nuclear fuel activities tomorrow unless it received European Union proposals today to break a diplomatic impasse over the country's atomic programme.
In London, the British Foreign Office said today that EU members Britain, France and Germany had informed Iran only that "full and detailed proposals" would be delivered in a week.
The EU plans to offer economic and political incentives in return for Iran's indefinite suspension of uranium enrichment, nuclear fuel reprocessing and related activities.
The EU and the United States suspect Iran wants to use these processes to make nuclear weapons and say if Iran restarts them, they will ask the UN Security Council to impose sanctions on the Islamic Republic. Tehran insists its programme is peaceful and it only wants nuclear power to generate electricity.
"If we do not receive the EU proposal today, tomorrow morning we will start part of (the) activities in Isfahan's uranium conversion facility," Ali Aghamohammadi, spokesman for the Supreme National Security Council, told state television.
The conversion plant near the central city of Isfahan takes processed uranium ore, mined in Iran's central desert, and turns it into uranium hexafluoride gas. This gas can be pumped into centrifuges that spin at supersonic speed to enrich uranium.
Enriched uranium is used in nuclear power plants, but if highly enriched can be used in atomic weaponry.
An EU diplomat familiar with the nuclear negotiations said any resumption of activities at the Isfahan plant would mean Iran had broken an agreement it made in Paris in November, 2004.
According to the agreement Iran committed "on a voluntary basis, to continue and extend its suspension to include all enrichment related and reprocessing activities" and "all tests or production at any uranium conversion installation".
The agreement also states: "The suspension will be sustained while negotiations proceed on a mutually acceptable agreement on long-term arrangements."
The EU diplomat said: "We've been absolutely clear all along that if they did something like this it would be considered a breach of our agreement."