The source said Washington had not decided what might be an acceptable commitment from Tehran in exchange for such a step, which would reverse former US President Donald Trump’s 2019 blacklisting of the group and draw sharp Republican criticism.

The move was the first time Washington had formally labeled part of another sovereign government as a terrorist group.

The source, who spoke on condition of anonymity, added the Joe Biden administration was weighing whether to drop the terrorist designation “in return for some kind of commitment and/or steps by Iran, with respect to regional or other IRGC activities.”

The Biden administration’s consideration of such a tradeoff was first reported by Axios, citing Israeli and US sources.

Multiple sources have stated dropping the designation is one of the last, and most vexing, issues in wider indirect talks on reviving the 2015 deal under which Iran limited its nuclear program in return for relief from economic sanctions.

Asked about the possibility of removing the IRGC from the US terrorism list, US State Department spokesman Ned Price declined comment beyond saying that sanctions relief is at the heart of negotiations to revive the nuclear deal.

Last week an Iranian official noted the IRGC’s removal from the blacklist had been under discussion as far back as June but that the issue had become more complicated after last summer’s election of Ebrahim Raisi as Iran’s president.

The Iranian official, who spoke on condition of anonymity, added the United States had made clear “they cannot remove it without major concessions from Iran,” a stance he said had been rejected by Iran’s lead nuclear negotiator, Ali Bagheri Kani.

Negotiations resumed in late November, with officials from other parties to the deal – Britain, China, France, Germany and Russia – as well as European Union officials coordinating the talks shuttling between US and Iranian representatives. An agreement would allow Iran to sell its oil abroad.