That sentiment was expressed at a meeting in Washington on 18 January between U.S. Secretary of State Condoleezza Rice and the visiting EU foreign policy chief, Javier Solana.
The West is concerned that Iran intends to develop an atomic weapon. Iran says its work is strictly for peaceful purposes.
Rice said the U.S. is continuing to talk to UN Security Council members Russia and China on what to do about Iran.
" I think they've both expressed their very grave concern about what Iran has done, and we'll continue to work with them on a future course," Rice said.
Iranian President Mahmud Ahmadinejad has condemned as politically motivated an EU resolution being drafted by Britain, France, and Germany in which the three countries call for Iran to be referred to the UN Security Council, which could impose sanctions on Iran.
(AP, dpa, Reuters)