"I don't think it will take us the same amount of time as it took the Biden administration to come," Khatibzadeh said, referring to US diplomats under President Joe Biden indirectly joining the Vienna talks.

"The government of (President) Ebrahim Raisi has been in power for less than 55 days... I don't think that the (return to talks) will take as much as 90 days," he added, indicating that Iran believes talks will be underway again by the second week of November.

It is the first time Iran has suggested a date for a possible return to the table.

The 2015 nuclear deal gave Iran sanctions relief in return for tight controls on its nuclear programme, monitored by the UN.

Then-US president Donald Trump withdrew from the multilateral deal and began reimposing sanctions in 2018.

Tehran has gradually rolled back its nuclear commitments since 2019.

Talks in Vienna to revive the deal have been stalled since June, when ultraconservative Raisi was elected as Iran's president. He took office in August.

Biden -- who took office in January -- has signalled a willingness to return to the deal and talks to that end began in April in Vienna, before they stalled.

The talks involve Iran and the remaining parties to the deal -- China, Russia, France, the UK and Germany -- but the US has not participated directly.