WASHINGTON — Talks on Iran’s nuclear program sputtered to a halt Saturday after diplomats reported scant progress in narrowing differences over proposals to limit Iran’s atomic advances in exchange for sanctions relief.
The negotiations in Almaty, Kazakhstan, ended in a frustrating muddle, with the sides describing the talks as constructive but ultimately fruitless in resolving a dispute that has raised fears of another military conflict in the Middle East. At the conclusion, the negotiators could not agree on dates for a new round of meetings, nor could they declare diplomacy at an impasse.
‘‘Over two days of talks we had long and intensive discussions on the issues,’’ Catherine Ashton, the European Union’s foreign policy chief, said at a news conference as the talks adjourned. ‘‘It became clear that our positions remained far apart.’’
Yet, despite the gloomy assessment, Western diplomats said the talks were useful, allowing a robust if sometimes contentious airing of differences between Iran and the six world powers that are seeking to extract nuclear concessions from the Islamic Republic.
A Russian diplomat at the talks, Deputy Foreign Minister Sergei Ryabkov, called the talks ‘‘certainly . . . a step forward,’’ and a senior US official described ‘‘quite substantive’’ exchanges with Iran as the discussions entered their second day.
The chief negotiator for Iran said, “Confidence building is a two-way road.’’
‘‘It is fair to say that both sides came away with a better understanding of the other’s thinking,’’ said the US official, who insisted on anonymity in describing sensitive diplomacy.
Acknowledging a ‘‘significant gulf’’ between the sides, the official said decisions on next moves would not be clear until the diplomats return to their capitals for consultations. ‘‘All of us need to evaluate what the next steps should be in this process and think through how we can more effectively get there,’’ the official said.
Iran’s chief negotiator, Saeed Jalili, alluded to remaining obstacles to an agreement in a news conference in which he repeatedly insisted on international recognition of Iran’s right to make enriched uranium.
Iranian officials have suggested they might accept demands that it freeze production of some of its enriched uranium as a ‘‘confidence-building’’ measure, but only if the West immediately lifts economic sanctions that have battered the country’s economy.
‘‘Confidence building is a two-way road and should include reciprocal and balanced actions,’’ Jalili told reporters. ‘‘It should not include depriving a nation of its rights, rather it should be based on mutual cooperation.’’
The talks appeared to be lurching toward failure within hours after the start of the meetings in a posh Almaty hotel. The six nations in the talks with Iran — the United States, Britain, China, France, Germany, and Russia — had called on it to respond to a detailed proposal that included halting production of a type of enriched uranium that is considered close to weapons-grade. In exchange, Iran was offered relief from some economic sanctions, with the promise of a more substantial easing in the future under a comprehensive deal aimed at lessening international anxiety over Iran’s nuclear intentions.
On Friday, Iranian diplomats unveiled what they described as a ‘‘comprehensive proposal’’ for settling the dispute, one that hinged largely on the demand for sanctions relief and recognition of Iran’s nuclear rights. But Western officials expressed bafflement with the offer, which diplomats said was merely a reworked version of Iran’s previous positions.
The failure of the sides to achieve tangible progress — or even a firm date for new talks — was seen as a disappointment for the Obama administration, though most experts had expected at best modest progress in nuclear talks until after the Iranian presidential election in June. Some said the White House will be pressured to further tighten the economic noose on Tehran.
Trita Parsi, an Iran expert who is critical of US sanctions policy, faulted both sides for continuing to talk past each other.
‘‘While the US has been focused on red lines, in Kazakhstan, the Iranians were looking for the finishing line,’’ said Parsi, author of ‘‘A Single Roll of the Dice,’’ a book on the Obama administration’s Iran policies. ‘‘Ultimately, all sides must take risks for peace.’’