Iranian officials have remained cautious in responding to Russia’s demands, but suggested on Thursday that there were still serious unresolved issues in the nuclear negotiations.
Tasnim news agency quoted an Iranian official saying that there were still important matters linked to guarantees and sanctions that had not been resolved.
Iran has also said it wants guarantees that no future US president will again abandon a nuclear deal.
Underscoring Iranian concerns, former US Vice President Mike Pence said on Wednesday that should Washington agree to a new accord and were the Republicans to take power again, they would “rip up any new Iran nuclear deal on day one”.
An Iranian official said there were still two to three difficult questions to resolve and that Tehran was now also demanding a change in the sequencing of how an accord should be implemented.
He said Iran wanted the issuing of oil waivers first and then Tehran to verify the move by exporting oil and getting petrodollars via the banking system.
European negotiators from France, Britain and Germany have temporarily left the talks as they believed they had gone as far as they could and it was now up to the US and Iran to agree on outstanding issues.
Russia’s envoy to the talks, Mikhail Ulyanov, on Wednesday evening dismissed any suggestion that Moscow was holding up an agreement and said a text was no longer final because there had been new demands by other participants.
“In view of the new circumstances and wave of sanctions against Russia we have the right to protect our interests in the nuclear field and wider context,” Ulyanov said.
He said the US and the EU had to make it clear that neither now nor in the future could sanctions hit the implementation of nuclear projects in Iran or, much more broadly, Russia’s trade and economic relations with Iran.
Western officials say Moscow is trying to reap extra benefits from its participation in the effort to restore the nuclear agreement, but that they would not play ball.