Britain, France and Germany are pressing ahead with a US-backed plan for a resolution by the UN nuclear watchdog's board criticising Iran for curbing cooperation with the agency, despite Russian and Iranian warnings of serious consequences.
The International Atomic Energy Agency's 35-nation Board of Governors is holding a quarterly meeting this week against the backdrop of faltering efforts to revive Iran's nuclear deal with major powers now that US President Joe Biden is in office.
Iran has recently accelerated its violations of the 2015 deal in an apparent bid to raise pressure on Biden, as each side insists the other must move first.
Tehran's breaches are a response to the US withdrawal from the deal in 2018 and the reimposition of US sanctions that had been lifted under it.
The latest breach was to scale back cooperation with the IAEA last week, ending extra inspection and monitoring measures introduced under the deal, including the power given to the IAEA to carry out snap inspections at facilities that have not been declared to be related to nuclear energy.
The three European powers, all parties to the 2015 deal, circulated a draft resolution for the Vienna meeting voicing "serious concern" at Iran's reduction of transparency and urging Iran to reverse its steps.
The draft, sent to IAEA board members and obtained by Reuters, also voices disquiet at the "lack of progress" in obtaining explanations from Iran about uranium particles found at three old sites, including two that the IAEA first reported on last week.
Iran has bristled at the prospect of such criticism, threatening to cancel a deal struck a week ago with the IAEA to temporarily continue many of the monitoring measures it had decided to end - a black-box-type arrangement valid for up to three months and aimed at creating a window for diplomacy.
Diplomacy, however, does not appear to be moving quickly if at all. Iran said on Sunday it would not take up a proposal by European Union foreign policy chief Josep Borrell to hold an informal meeting with other parties to the nuclear pact and the United States.
It is unclear how many countries would support a resolution. In its own position paper obtained by Reuters before Iran's announcement, Russia warned that a resolution could hurt efforts to revive the deal, formally known as the Joint Comprehensive Plan of Action (JCPOA), and that it would oppose it.
"Adoption of the resolution will not help the political process of returning to the normal comprehensive implementation of the JCPOA," Russia's note to other member states said.
"On the contrary it will hugely complicate those efforts undermining the prospects for the restoration of the JCPOA and for normal cooperation between Iran and the Agency."