ALMATY, Kazakhstan -- As negotiations resumed here on Friday between Iran and the six world powers demanding that it curb its nuclear program, Iran said it had put forward a new "comprehensive proposal" that it hoped would "establish a new bedrock for cooperation."
The other negotiators, however, described Iran's statement as a bewildering surprise and said they had not received any concrete new proposal. An afternoon negotiating session ended with little sign of additional clarity, and though officials said the talks would continue on Saturday, they seemed to have hit a roadblock.
A Western official, speaking on the condition of anonymity, said the Iranian remarks essentially echoed a position articulated at talks in Moscow last June. "We are somewhat puzzled by the Iranians' characterization of what they presented at this morning's plenary," the official said. "There were some interesting but not fully explained general comments on our ideas."
The announcement of a new proposal, by Ali Baqeri, deputy head of the Iranian delegation, came after the opening session of talks as Iranian officials took a break for lunch and prayers. Mr. Baqeri did not offer any details. In the past, expansive language about a "comprehensive" solution has involved additional complicated issues, like the civil war in Syria, that seemed to dim rather than improve the prospects for an agreement.
With American and European officials demanding that Iran show willingness to address international concerns, Mr. Baqeri suggested that the Iranian delegation had gone even further. "These steps are referred to as confidence-building measures, but they are part of a comprehensive set of measures," he said at a news conference at a central Almaty hotel. "This is not distinct from that comprehensive step."
But at a second briefing at the end of the day's talks, Mr. Baqeri acknowledged that the proposal put on the table had roughly the same contours as the plan offered in Moscow. "The Islamic republic of Iran this morning proposed a practical method to implement the Moscow plan in a smaller scale," he said.
Expectations for this latest round of negotiations have been modest at best, with little sign that the Iranian government was ready to accept an offer made by the six powers at the last round of talks in February: restrictions on its supply of dangerous enriched uranium in exchange for a modest easing of international sanctions.
"We had a long and substantial discussion on the issues, but we remain a long way apart on the substance," a Western diplomat said Friday. "We are now evaluating the situation and will meet again tomorrow."
Although American and European officials arrived expressing guarded hope of a breakthrough, the lead Iranian negotiator began his visit with a speech to university students in which he insisted on his country's unfettered right to develop a civilian nuclear program and accused the larger powers of hypocrisy because they have nuclear arms.
In the speech, at Al-Farabi Kazakh International University on Thursday, the Iranian negotiator, Saeed Jalili, said that it was possible to "unlock" the stalemate in the talks if the international negotiators -- Britain, China, France, Germany, Russia and the United States -- would simply "accept the inalienable rights" of Iran, specifically the right to enrich uranium.
In complaining of hypocrisy, Mr. Jalili singled out the United States for criticism and called the new round of talks here "a test for American behavior."
But American and European officials have insisted that the test is for Iran, which must respond to an offer presented here in Almaty at the last talks in February and explained in greater detail at a meeting with technical experts in Istanbul last month.
"How far we get," a senior Obama administration official said before leaving Washington for Almaty, "depends on what the Iranians come back with in terms of a response on the substance to our proposal."
That proposal would impose constraints on Iran's supply of enriched uranium and require Iran to shut its enrichment plant at Fordo, which is built deep underneath a mountain. Iran would also have to agree to a series of steps making it more difficult to resume producing nuclear fuel quickly. The proposal would allow Iran to keep a small amount of uranium enriched to 20 percent purity for use in a reactor to produce medical isotopes. Such uranium can be converted to weapons grade with relatively modest additional processing.
While Iran says its nuclear program is exclusively for civilian purposes, Western officials suspect that Tehran is seeking the technology for nuclear weapons.
As the talks opened Friday, Michael Mann, the spokesman for Catherine Ashton, the European Union's foreign policy chief and chairwoman of the group of six powers, said: "What we are hoping is that the Iranian side will come back to us today with a clear and concrete response." Mr. Mann, speaking at a news conference, declined to speculate on the response should Iran initially not offer a concrete counterproposal early in the session. But he said the process at this point hinged on the Iranian side.
"The confidence-building measure has to come from Iran," Mr. Mann said.
Iran is in the midst of a contentious presidential election, a process that inevitably complicates any negotiations in the international arena.
The senior Obama administration official said that so long as Iran remained in defiance of the international community, painful sanctions including Western restrictions on importing Iranian oil would remain in place and potentially become even more severe. "That pressure only will increase if Iran does not begin to take concrete steps and concrete actions," the official said. "Sanctions as well as the isolation Iran has created for itself continue to have their effect, and oil importers have continued to make reductions."
The official noted Iranian statistics showing inflation has soared by 31.5 percent over the past year and continues to rise. The value of its currency, the rial, has plummeted since sanctions began.
As in February, the negotiations are taking place in Kazakhstan, the former Soviet republic that was once the main site for testing of nuclear weapons by the Soviet Union. It takes pride in its role on the issue of nuclear nonproliferation, including the elimination of missiles left behind by the Soviets.
Russian and Chinese officials have been more restrained in their comments ahead of the current round of talks.
Earlier this week, a deputy Russian foreign minister, Igor Morgulov, said that an agreement ultimately would have to recognize Iran's right to the use of atomic power for energy and medicine. Russia has been a partner in the construction and operation of Iran's existing Bushehr nuclear power plant.
"We believe a long-term settlement should be based on the recognition of Iran's unconditional right to develop its civilian nuclear program, including the right to enrich uranium" provided that all nuclear activity is put under supervision of the International Atomic Energy Agency, Mr. Morgulov told the Interfax news agency.
Mr. Morgulov said that the Russian delegation was working in close consultation with its Chinese counterparts. "We highly value a close dialogue with China on the situation surrounding the Iranian nuclear program," he said. "Our positions coincide in many aspects."
A spokesman for the Russian Foreign Ministry, however, said expectations were modest for the Almaty talks. "Regrettably, the sides have not yet started to move toward formulating compromise-based agreements," the spokesman, Aleksandr Lukashevich, said in Moscow on Thursday.
Gary Samore, who oversaw nuclear arms control issues for the White House during the first Obama administration and is now executive director for research of the Belfer Center for Science and International Affairs at Harvard University, said in Washington this week that he had very low expectations for the talks and that both sides had reasons to prolong the diplomatic wrangling.
"The Iranians use diplomacy in an effort to try to show that there's progress and therefore no further sanctions are justified, and to the extent that it looks like there's progress it helps maintain the value of the rial," Mr. Samore said, while the United States and its partners "use diplomacy in order to demonstrate that Iran is being intransigent and unreasonable and therefore more sanctions are required."
"That process is going to continue," Mr. Samore added.
Michael Gordon contributed reporting from Washington.
This article originally appeared in The New York Times.