The European Union insisted on Monday that Iran comply with an international resolution that it freeze all sensitive nuclear activities but said it was studying a new offer of talks from Tehran.

British Foreign Minister Jack Straw said the EU had not “so far” discussed economic or diplomatic sanctions on Iran if it did not comply with the resolution by the International Atomic Energy Agency (IAEA).

“What we would like to see is Iran implementing the terms of the resolution of the board of governors of the IAEA that was passed in September,” Straw, whose country holds the rotating presidency of the 25-member EU, said. “(The possibility of sanctions) has not been discussed so far. I’m not going to speculate on the future,” he told a news conference after a meeting of EU foreign ministers.

Straw said the EU was studying a letter by chief Iranian nuclear negotiator Ali Larijani to Britain, Germany and France seeking a revival of talks which broke down in August when Iran resumed uranium ore conversion.

It was the first direct approach by Iran since President Mahmoud Ahmadinejad, took office in August. Straw did not say when or how the EU might respond.

US officials are sceptical about the new Iranian move.

“Is this real or cosmetic? It’s too early to say. So we are letting the Europeans take the lead on this because they are doing the negotiating,” said a State Department official who requested anonymity.