Europe is warning Iran that future relations depend on the Islamic Republic restricting its nuclear activities.The 25 EU foreign ministers have urged Tehran to keep its promise to suspend the enrichment of uranium which could be used to develop nuclear weapons. British Foreign Secretary Jack Straw said he did not expect talks this Wednesday in Geneva between the UK, France and Germany and Iran to be easy. And if Tehran went ahead with a threat to resume uranium conversion at a plant in Isfahan? An EU official said there was general agreement on referring Iran to the U.N. Security Council for possible sanctions. The EU hopes for an improved negotiating atmosphere after Iran holds elections in mid-June.