World powers will resume talks on the Iran nuclear deal in Vienna this week with mediators set to hold "separate contacts" with the United States.
Diplomatic efforts around the US's potential return to the pact will intensify alongside Tuesday's talks in the Austrian capital, the European Union said, after initial online discussions on Friday.
The talks between representatives of the EU, Britain, France, Germany, Russia, China and Iran came as US President Joe Biden's administration looks to engage Tehran in negotiations over both sides resuming compliance with the deal.
Talks may be off to a difficult start. On Saturday, Iranian Foreign Ministry spokesman Saeed Khatibzadeh reiterated the regime's maximalist position, saying that Tehran was opposed to any gradual easing of sanctions.
"No step-by-step plan is being considered," Mr Khatibzadeh told Press TV. "The definitive policy of the Islamic Republic of Iran is the lifting of all US sanctions."
The aim of the talks in the Austrian capital is to reach an agreement within two months, according to a senior official with the EU, the co-ordinator of the negotiations.
US President Joe Biden's predecessor Donald Trump withdrew from the deal in 2018 and reimposed sanctions. Iran has breached some of the pact's nuclear restrictions in retaliation.
An EU statement said that powers at Friday's meeting “recognised the prospect of a full return of the US" to the Joint Comprehensive Plan of Action, the formal name of the 2015 nuclear deal.
They also “underlined their readiness to positively address this in a joint effort” and “emphasised their commitment to preserve the JCPOA”.
“Participants agreed to resume this session of the Joint Commission in Vienna next week, in order to clearly identify sanctions lifting and nuclear implementation measures, including through convening meetings of the relevant expert groups,” it said.
“In this context, the co-ordinator will also intensify separate contacts in Vienna with all JCPOA participants and the US.”
The US confirmed it would take part in the diplomatic efforts and offered to sit down with Iran.
"These remain early days and we don't anticipate an immediate breakthrough as there will be difficult discussions ahead. But we believe this is a healthy step forward," US State Department spokesman Ned Price said.
The US special envoy for Iran, Robert Malley, welcomed negotiations and called them a step "in the right direction".
Mikhail Ulyanov, Russia’s ambassador to the UN’s International Atomic Energy Agency, said that talks were “on the right track”.
"Discussions were quite businesslike and will continue," he said.
"The impression is that we are on the right track but the way ahead will not be easy and will require intensive efforts. The stakeholders seem to be ready for that."
Iran’s Foreign Minister Mohammad Javad Zarif said the aim of next week’s meeting was to “rapidly finalise sanction-lifting”, which he said would be followed by “Iran ceasing remedial measures”.
Mr Zarif said there would be no meeting between Iran and the US, calling it “unnecessary”.
Iran’s deputy foreign minister Abbas Araghchi, a senior negotiator, told Iranian TV that Friday’s talks were “frank and serious”.
"Iran will suspend its steps [scaling back compliance with deal terms] as soon as sanctions are lifted and this is verified," Mr Araghchi told the meeting.
Germany’s Foreign Ministry welcomed the continuation of talks in Vienna, saying it had “worked intensively” with Britain and France towards preserving the deal.
“We have no time to lose. An agreement that is once again fully respected would be a plus for the whole region’s security and the best foundation for discussions about other important questions on regional stability,” a German statement said.
China on Friday called for the US to lift all "illegal sanctions" on Iran, saying the country’s nuclear issue was at a “critical stage”.
Foreign Ministry spokeswoman Hua Chunying blamed Washington’s unilateral exit from the deal as the “root cause” of the problem, and said China welcomed the return of the US.
Under the 2015 agreement, economic sanctions on Iran were lifted in return for curbs on Iran's nuclear programme.
Friday’s talks were chaired by EU official Enrique Mora, the political director of the bloc’s External Action Service, on behalf of the EU’s High Representative for Foreign Affairs, Josep Borrell.
French Foreign Ministry spokeswoman Agnes von der Muhll said European powers were working closely with Russia and China to find a solution to the deadlock.
"These exchanges are more than necessary because Iran has not accepted taking part in direct contacts between the other participants and the US ... which would have eased discussions," she said.