The US team tasked with negotiating a nuclear deal with Iran is split over its current strategy with some diplomats wanting a tougher approach to Tehran in the negotiations, according to a media report.
American diplomats are split on whether to continue with the talks after repeated stalls, blamed on Tehran, and about how strictly to apply current US sanctions on Iran, The Wall Street Journal reported.
The US is currently renegotiating a return to the 2015 nuclear deal with Iran, aimed at curbing its nuclear programme in exchange for sanctions relief.
Former President Donald Trump withdrew from the deal in 2018 with Iran ramping up its nuclear activities ever since and Washington enforcing tough sanctions on Tehran.
Divisions on these issues have seen Richard Nephew, the deputy special envoy for Iran, leave the negotiating team, headed by veteran US diplomat Robert Malley, over the weekend, WSJ learned.
Nephew had argued for a tougher stance toward Iran, while two other officials have quit the team for the same reason, according to the report.
A State Department official confirmed that Nephew had left the negotiating team and that another official asked to be removed from the talks taking place in Vienna.
No other member of the team had left for "anything other than normal personnel reasons", the source told the business daily.
Iran has so far refused to meet US officials in the talks, although Iran Foreign Minister Hossein Amir-Abdollahian said his team could if negotiations continue.
Some US lawmakers have been critical of the new negotiations with Iran, particularly after accusations that Iran is deliberately stalling talks while making advances in its nuclear activities.
Iran is accused by US regional allies of wanting to build a nuclear bomb, which Tehran strongly denies.