Tehran said on Wednesday it was scrutinising US proposals to resume a controversial 2015 nuclear deal that could ease sanctions on the Iranian tanker fleet.

Any return to the pact could see Iran exporting an extra 1m to 1.5m barrels per day of crude within months, according to analysts, in return for closer scrutiny of the country’s nuclear programme.

Most of the parties involved in the deal had given their backing to the programme but US President Joe Biden – a strong backer of the plan – faces strong political opposition at home and fierce criticism from ally Israel.