Iran's supreme leader Ayatollah Ali Khamenei warned European powers yesterday that they must take their nuclear negotiations with Iran seriously, otherwise Tehran would reconsider its co-operation. "The Europeans negotiating with Iran should know that they are dealing with a great, cultured nation ... if Iranian officials feel that there is no seriousness in the European negotiations, the process will change," Khamenei was quoted as saying by the Iranian media.His comments followed the emergence of reports that the EU was hardening its stance towards Iran and calling on Tehran to completely dismantle its nuclear fuel programme in order to guarantee that it does not seek atomic weapons. Iran, accused by Washington of trying to build an atomic bomb, has suspended uranium enrichment as a confidence-building measure but the EU now wants the Islamic republic to definitively abandon enrichment as well as any activities for making plutonium. Khamenei told the Europeans that "wasting time could not impede Iran's path to nuclear technology since it is a part of its national interest." Iran insists that its nuclear activities are peaceful and that the nuclear Non-Proliferation Treaty guarantees its right to peaceful enrichment activities.