Iran said talks with France, Germany and Britain on Thursday on its nuclear program were "promising" but more work was needed to settle the 12-year standoff, the official IRNA news agency reported.
Political directors from Iran and the three European countries held talks in Istanbul in an effort to overcome the remaining gaps on a long-term nuclear deal by a self-imposed June 30 deadline.
"The talks were very useful, positive and promising but still we are not in a position to say we made progress," IRNA quoted senior Iranian nuclear negotiator and deputy Foreign Minister Abbas Araqchi as saying after the talks.
"While discussing details ... we face more diversity of views," he added. "We can reach an agreement if all the parties involved show strong political will to end this issue."
Western governments suspect Iran of aiming to acquire nuclear weapons. Tehran insists the goals of its nuclear work are purely civilian and peaceful.
Negotiators from Iran and six major powers failed to meet a self-imposed deadline in November to clinch a final agreement seen as crucial to reducing the risk of a wider Middle East war.
Under a Nov. 24, 2013 accord with Britain, China, France, Germany, Russia and the United States, Iran halted its most sensitive nuclear activity and took other steps in exchange for some easing of economic sanctions.
