The team of International Atomic Energy Agency scientists who arrived in Tehran early Sunday will spend three days in Iran as they inspect the facility being built inside a mountain near the holy city of Qom, south of the capital.
Four inspectors from the UN's atomic energy agency are in Iran to visit the controversial second uranium-enrichment plant. The trip came despite Tehran postponing its response to a UN-drafted plan for it to cut a stockpile of nuclear fuel.
At the end of a round of nuclear talks in Vienna this week, Iran appeared to reject a UN-drafted plan for it to cut a stockpile of nuclear fuel, and instead said it wanted to buy nuclear fuel from abroad.
At the end of three days of nuclear negotiations in Vienna, Iranian negotiators face a Friday deadline to approve a draft deal to have Iran ship its uranium abroad for processing. But there were doubts about a deal.