Russia regrets that Iran has apparently rejected a UN-brokered nuclear fuel exchange deal to ease the standoff over its atomic programme, Foreign Minister Sergei Lavrov said on Friday.

“We regret that Iran — as far as we can see — does not consider it possible to agree to the formula that it was offered,” Lavrov told a news conference.

Under the plan, Iran would hand over most of its stocks of low-enriched uranium in return for the supply by France and Russia of nuclear fuel enriched to the higher level required for a Tehran research reactor.

He noted that the UN Security Council had the capacity to “study further measures on Iran” but once again did not come out explicitly in support of further UN sanctions against the country.

“Acting with a logic of punishing Iran… is not a sober approach,” he said.