Iran should show flexibility in negotiations on resolving the dispute over its nuclear activities in order to achieve "substantial progress," Catherine Ashton, the European Union's top diplomat, said Wednesday. Ashton told a UN Security Council session at UN headquarters in New York that Iran's nuclear issues remain at the top of the European Union agenda. Iran is to start talks on February 26 in Kazakhstan with Britain, France and Germany, representing Europe; and the United States, Russia and China. "We hope Iran will come to this negotiation with flexibility and that we can make substantial progress," said Ashton, who is the High Representative of the European Union for Foreign Affairs and Security Policy. "Our strength and credibility in negotiating with Iran derives from the E3+3, but also from the more general support that we receive from the international community," dpa quoted Ashton as saying.