The US is pushing Iran to stop selling armed drones to Russia as part of discussions on a broader unwritten understanding between Washington and Tehran to de-escalate tensions, the Financial Times reported on Wednesday.
Washington also wants Tehran to stop selling spare parts for the drones, which Moscow is using in the war in Ukraine, the report said, citing an Iranian official and another person familiar with the talks.
The White House and Iran's Foreign Ministry did not immediately respond to a request for comment.
The news comes as Washington and Iran are trying to ease tensions and revive broader talks over Iran's nuclear programme.
US Secretary of State Antony Blinken said on Tuesday that he would welcome any Iranian steps to de-escalate its “growing nuclear threat”.
Under the 2015 Joint Comprehensive Plan of Action with the US, China, Russia, France, the UK and Germany, plus the EU, Tehran agreed to limits on its nuclear programme in exchange for sanctions being eased.
When the US withdrew from the deal in 2018 and reimposed sanctions, Iran flouted previously agreed restrictions.
Tehran says its nuclear programme is for civilian purposes.
Discussions on reviving a nuclear agreement have taken place alongside the negotiations on a prisoner exchange deal last week, the newspaper said.
Iran allowed four detained US citizens to move into house arrest from Tehran's Evin prison while a fifth was already under home confinement.
Last week, sources told Reuters that Iran may free five detained US citizens as part of a deal to unfreeze $6 billion in Iranian funds in South Korea.