International negotiations on the Iranian nuclear programme have gone into their second and final day in Almaty with little sign of progress.
Iran is being asked to give up work on the most sensitive parts of its nuclear activities in return for the relaxation of international sanctions.
A Western diplomat said the Iranians had given no clear response.
World powers suspect Iran of a covert nuclear weapons programme while Tehran insists its intentions are peaceful.
Saturday’s round of talks in the Kazakh capital opened with a meeting between Iranian chief negotiator Saeed Jalili and EU foreign policy chief Catherine Ashton.
Iran then went into full talks with the so-called P5+1 group comprising the five permanent members of the UN Security Council – the US, Russia, China, the UK and France – plus Germany.
‘Somewhat puzzled’
After Friday’s round, Tehran said it had offered “specific plans” but a Western diplomat who briefed journalists anonymously said there had been no “clear and concrete response”.
The P5+1 group was “somewhat puzzled by the Iranians’ characterisation of what they presented” at the morning session, the diplomat added.
“There were some interesting but not fully explained general comments on our ideas. It was mainly a reworking of what they said [earlier] in Moscow.”
Russian Deputy Foreign Minister Sergei Ryabkov said for his part: “Iran has given an answer to the proposals of the six powers.
“It is the kind of answer that creates more questions… but this shows that the negotiations are serious.”
Saeed Jalili said on Thursday that Iran had a right to enrich uranium that must be accepted.
At a previous round of talks in Kazakhstan in February, the P5+1 tried to push Tehran to halt production and stockpiling of uranium enriched to 20% – a step away from achieving a nuclear weapons capability.
The P5+1 also demanded Iran shut down the Fordo underground enrichment facility.
In return the world powers suggested easing tough economic sanctions imposed on Iran in response to its nuclear programme.
Iran’s economy has been squeezed, with oil revenue slashed, the currency nose-diving in value and unemployment growing.