Iran says it has agreed with Russia to increase the number of countries joining a plan for Tehran to carry out sensitive nuclear fuel work in Russia.
Speaking to reporters Saturday in Tehran, Iranian Foreign Minister Manouchehr Mottaki said possible locations for uranium enrichment are still under review.
Moscow's idea to have Iran enrich uranium in facilities in Russia where the work can be closely monitored is seen as a way out of a growing crisis over Tehran's nuclear ambitions. The United States, China and the European Union support the proposal.
Meanwhile, the chief of Iran's Revolutionary Guards, General Yahya Rahim Safavi, said Saturday his country would use ballistic missiles to defend itself if attacked.
President Bush told the CBS television network Friday he is open to all possible options for dealing with Iran, including military intervention. But he said that would be the last option.