Representatives of China, France, Germany, Russia, the United Kingdom and Iran -- the countries still party to the agreement after the US left -- will attend.

"Participants will discuss the prospect of a possible return of the United States to the JCPOA, and how to ensure the full and effective implementation of the agreement by all sides," the statement said, referring to the deal by its initials.

The meeting brings together the body that oversees the implementation of the JCPOA, which has been under threat since former US president Donald Trump pulled out in 2018 and Iran began to resume nuclear activities it had scaled back.

The online meeting will be chaired by senior EU diplomat Enrique Mora on behalf of EU foreign policy chief Josep Borrell.

Trump denounced the 2015 accord, which saw Iran granted relief from international sanctions in exchange for accepting limits on its nuclear programme, which Western powers feared would lead to it acquiring an atomic weapon.

But new US President Joe Biden has promised to rejoin the agreement on the condition that Tehran first returns to respecting the commitments it dropped in retaliation for Trump's decision.

Earlier this month, supreme leader Ayatollah Ali Khamenei said Iran may return to full compliance if Tehran deems Washington has honoured its commitments.

The agreement was signed by Iran in Vienna in 2015 with the major powers United States, China, Russia, Germany, France, United Kingdom, under an EU chair.

It was designed to prevent the Islamic Republic from acquiring a nuclear arsenal by imposing strict limits on its nuclear programme and force it to remain exclusively civilian and peaceful.