World powers and Iran still appear far apart today as negotiations on Tehran's nuclear programme aimed at calming tensions could boil over into war.
As talks get under way in Kazakhstan, the six nations - the United States, Russia, China, France, Britain and Germany - are seeking a concrete response from Iran to their February offer to ease sanctions if it stops its most sensitive nuclear work.
Iranian negotiators said they have outlined their own "specific" proposals, but a Western diplomat said they had still not responded clearly to the initiative from the big powers.
The dissonant views suggested the two sides have not narrowed differences that have bededvilled a decade of on-off talks.
"We are somewhat puzzled by the Iranians' characterisation of what they presented at this morning's plenary," a Western diplomat said. "There has not yet been a clear and concrete response to the...proposal (from the six powers)."
Iran's deputy negotiator Ali Bagheri did not say whether the offer was acceptable, but told reporters his side had made "specific proposals...for the start of a new round of cooperation".
"Naturally, the talks will continue today and, if necessary tomorrow, until the two sides exchange their views and until a new platform for cooperation is formed," he said after talks paused for Iranian negotiators to join Friday prayers at Almaty's main mosque.
The dispute centres on Iranian efforts to enrich uranium, which world powers suspect are part of a covert drive to achieve atom bomb capability. The UN Security Council has demanded that Iran stop the process, in several resolutions since 2006.
Iran argues it has the right to enrich uranium for peaceful purposes under international law and denies its nuclear work has military aims. It has refused to change course unless the big powers recognise its right to enrichment and lift sanctions.
Stakes are high because Israel, widely assumed to be the Middle East's only nuclear-armed power, has threatened to bomb the Islamic Republic's atomic sites if diplomacy fails to rein in a foe which it sees as bent on its destruction.
Chances for a quick breakthrough are seen as scant, with Iran not expected to make any major decisions on nuclear policy until after its presidential election in June.
Western diplomats are hoping at least for serious discussion of their February proposal, under which Iran would have to close a nuclear facility and ship some enriched uranium stockpiles abroad in return for modest relief on sanctions on Iranian petrochemicals and trade in gold and other precious metals.