Officials from Iran, China, Russia, France, Germany and Britain will meet online on Friday to discuss a possible US return to the 2015 nuclear deal, the EU said on Thursday.
The Biden administration has been looking to engage Iran in talks over both sides resuming compliance with the deal.
Under the agreement, economic sanctions on Tehran were lifted in return for curbs on Iran's nuclear programme.
US President Joe Biden's predecessor, Donald Trump, withdrew from the deal in 2018 and reimposed US sanctions, prompting Iran to breach some of the pact's nuclear restrictions in retaliation.
The US and Iran have yet to agree on meeting to try to revive the deal and are communicating through European nations, western officials said.
"Participants will discuss the prospect of a possible return of the US to the [deal] and how to ensure the full and effective implementation of the agreement by all sides," the EU said.
Diplomatic sources said Britain, France and Germany held talks with Iran on Monday and one said there had been talks about a proposal from Tehran.
France's Foreign Ministry spokeswoman Agnes von der Muhll said European powers were working closely with Russia and China – the other parties to the deal – 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 United States ... which would have eased discussions," she said.
Ms von der Muhll said that they were looking at alternative formats to enable talks.
US State Department spokesman Ned Price said the US welcomed the meeting as "a positive step".
"We have been clear for weeks now that we are ready to pursue a return to compliance with our [deal] commitments, consistent with Iran also doing the same," Mr Price said.
He said Washington was willing to achieve that "through a series of initial mutual steps".
