ALMATY — Iran gave an upbeat assessment of two days of nuclear talks with world powers that ended Wednesday, but Western officials said Tehran must start taking concrete steps to ease mounting concerns about its atomic activity. The first negotiations between Iran and six world powers in eight months ended without a breakthrough in Almaty, but they agreed to meet again at expert level in Istanbul next month and resume political discussions in the Kazakh city on April 5. Israel, assumed to be the Middle East's only nuclear-armed power, is watching the talks closely. It has strongly hinted it might attack Iran if diplomacy and sanctions fail to stop it from acquiring nuclear weapons. Iran denies any such aim. Iran's foreign minister said he was optimistic an agreement could be reached with the powers — the United States, France, Russia, Britain, Germany and China — on the country's disputed nuclear program. “Very confident,” Ali Akbar Salehi told Reuters when asked on the sidelines of a UN conference in Vienna how confident he was of a positive outcome. The six powers offered at the Feb. 26-27 Almaty meeting to lift some sanctions if Iran scaled back nuclear activity that the West fears could be used to build a bomb. Tehran did not agree to do so and the sides did not appear any closer to a deal to resolve a decade-old dispute that could lead to another war in the Middle East if diplomacy fails. But Iran still said the talks were a positive step in which the six powers tried to “get closer to our viewpoint”. Western officials had made clear they did not expect major progress in Almaty, aware that the closeness of Iran's presidential election in June is raising political tensions in Tehran and makes significant concessions unlikely. “I hope the Iranian side is looking positively on the proposal we put forward,” said European Union foreign policy chief Catherine Ashton, who led the talks on behalf of the powers. “We have to see what happens next.” The US did not expect a breakthrough and “the result was clearly in line with those expectations,” a senior US official said. The meeting was “useful” as the two sides agreed dates and venues for follow-up talks but there was a need for progress on confidence building measures, the official added. — Reuters