A telephone call between Iranian Foreign Minister Hossein Amir-Abdollahian and Russian counterpart Sergei Lavrov, which Moscow said was requested by Tehran, came just weeks before the talks reopen in Vienna on November 29 after a five-month gap.

"The rapid approach of the talks requires the European and American sides to adopt a constructive and realistic approach, avoiding excessive demands that go beyond the terms of the nuclear agreement" struck in 2015, the Iranian minister said, according to a ministry transcript.

The Russian foreign ministry said the two "sides spoke in favour of restoring the nuclear deal in its original, balanced configuration, approved by the UN Security Council".

"They confirmed that this is the only correct way to ensure the rights and interests of all participants of the comprehensive agreements."

The nuclear talks, which are being brokered by European Union mediators as Tehran refuses to deal with US negotiators directly, are aimed at bringing Washington back into a 2015 agreement with Iran that was abandoned by former US president Donald Trump.

The remaining parties to the agreement -- Britain, China, France and Germany as well as Russia -- are also taking part.

President Joe Biden has said he is ready to rejoin the deal, under which Iran agreed to strict limits on its nuclear activities in exchange for relief from sweeping sanctions.

But the two sides remain at odds over the details.

Iran wants a lifting of all US sanctions which were imposed after Trump's withdrawal.

The Biden administration says it will only negotiate measures taken by its predecessor over the nuclear programme, not steps imposed over other concerns such as human rights.

Tehran also wants commitments that the United States will remain bound by the deal -- an unlikely proposition in Washington, where Trump's Republican Party fiercely opposes Biden's diplomacy with Iran.

Washington insists Tehran must return to full compliance with the limits on its nuclear programme it agreed in 2015, and has warned repeatedly that the window of opportunity for a deal is closing fast.

Amir-Abdollahian said Saturday that Tehran would return to full compliance just as soon as Washington did so too.

"If the US side returns fully to its obligations and makes no other demands, Iran will honour its obligations too."