Fresh talks on Iran deal next week in Vienna
Participants would meet in the Austrian capital "to clearly identify sanctions lifting and nuclear implementation measures, including through convening meetings of the relevant expert groups", a statement said.
"The coordinator will also intensify separate contacts in Vienna with all JCPOA participants and the United States," the European Union said, referring to the deal by its initials.
The announcement came after a video conference of signatories to the 2015 accord, as they look to bring Washington back on board following former leader Donald Trump's decision to withdraw.
Iranian Foreign Minister Mohammad Javad Zarif said the meeting would take place Tuesday and insisted the aim was to "rapidly finalise sanction-lifting & nuclear measures for choreographed removal of all sanctions, followed by Iran ceasing remedial measures".
"No Iran-US meeting. Unnecessary," he wrote on Twitter.
New US President Joe Biden has promised to rejoin the agreement on condition Iran first returns to respecting the commitments abandoned in retaliation for Trump pulling out.
But Tehran says Washington has to lift international sanctions that were reimposed by Trump before it will make any moves to get back in line, and is refusing to hold direct negotiations with the US.
Senior EU diplomat Enrique Mora, who chaired the talks due to Brussels' role as coordinator, described Friday's virtual meeting as "positive", but warned there was much left to do to revive the deal.