Talks between Iran and world powers on a deal to allay concerns about Tehran's nuclear drive started well on Monday, the UN atomic agency chief said, despite Iran's reported refusal to negotiate with France.
The meeting hosted by the International Atomic Energy Agency (IAEA) offered the first chance to build on proposals raised at Geneva talks on October 1 to defuse a standoff over suspicions Iran's uranium enrichment programme is covertly intended to develop nuclear weapons.
Iran agreed then to UN inspections at a hitherto hidden nuclear site, and in principle to sending low-enriched uranium abroad for processing into fuel for a Tehran reactor producing medical isotopes.
The West hopes the step will minimise the risk of Iran refining the material to high purity suitable for bombs.
"We're off to a good start. We have had a constructive meeting. Most technical issues have been discussed. We will continue the meeting at 10am tomorrow," Mohamed ElBaradei told reporters in Vienna.
Ali Asghar Soltanieh, Iran's envoy to the IAEA, endorsed ElBaradei's remarks, saying he was speaking on Tehran's behalf.
The meeting of Iranian, Russian, French and US officials started in Vienna shortly after state-run Iranian television said Tehran would not deal directly with France since it had failed to deliver nuclear materials in the past.
A senior Western diplomat said there were no grounds "to put out a gloom and doom message" about the gathering.
"Everyone at the table was making their points and listening to one another. It's too early to tell the outcome. But there is nothing to prevent the talks ultimately moving forward."
But Iran, which says it is enriching uranium only for electricity uses, struck a defiant tone before the meeting.