A senior Iranian official has confirmed that Tehran would return to its nuclear deal commitment only if it got $US15 billion ($A22 billion) for oil sales over four months, as stipulated in a draft French plan to salvage the accord, the Fars news agency said.

France has proposed offering Iran about $US15 billion in credit lines until year-end if Tehran comes fully back into compliance with its 2015 nuclear deal, a move that hinges on Washington not blocking it.

“Our return to the full implementation of the nuclear accord is subject to the receipt of $US15 billion over a four-month period, otherwise the process of reducing Iran’s commitments will continue,” Fars quoted Deputy Foreign Minister Abbas Araqchi as saying.

“Either Europe has to buy oil from Iran or provide Iran with the equivalent of selling oil as a credit line guaranteed by Iran’s oil revenues, which in some sense means a pre-sale of oil,” Araqchi added.

Iran’s vital oil sales have plummeted since the United States withdrew from the nuclear deal last year and reimposed sanctions on Tehran.

But Araqchi said there were still “serious disagreements on the agenda” of any future talks between Iran and its nuclear deal partners.