GENEVA - Iran and major powers made "limited" progress on Sunday in narrowing differences over its nuclear program, but agreed to step up efforts as the Obama administration lobbied to stave off fresh sanctions against the Islamic Republic, diplomats said.The Geneva negotiations, held at the level of political directors, are the culmination of five days of diplomacy in the Swiss city and Paris, including lengthy meetings between US Secretary of State John Kerry and Iranian Foreign Minister Mohammad Javad Zarif."Substantive progress is limited, experts will continue tomorrow morning. It is fair to say that everybody is committed to stepping up efforts," a diplomat told Reuters as deputy ministers began a final session late on Sunday afternoon.
