The US has sent Iran a proposal for a nuclear deal between Tehran and Washington, the White House confirmed on Saturday.
Iranian Foreign Minister Abbas Araghchi said he had been presented with "elements of a US deal" by his Omani counterpart Badr Albusaidi during a short visit to the Iranian capital.
It comes after a report by the UN nuclear watchdog said Iran had further stepped up its production of enriched uranium, a key component in the making of nuclear weapons.