Foreign Minister Abbas Araqchi and U.S. Special Envoy to the Middle East Steven Witkoff are leading the two delegations in the talks on Sunday.
Oman’s Foreign Minister Badr bin Hamad Al Busaidi has been acting as an intermediary.
Earlier, Araqchi met with his Omani counterpart and expressed gratitude to Al Busaidi and the Omani government for hosting and facilitating the Iran-U.S. talks.
The senior Iranian diplomat also reiterated the Islamic Republic’s principled stance on the negotiations.
Before departing for Muscat, Araqchi told reporters in Tehran that uranium enrichment is a national achievement attained at great cost, including the sacrifices of nuclear scientists, and is therefore unequivocally non-negotiable.
He expressed hope that this round of talks would proceed constructively, emphasizing that negotiation-related matters should be addressed at the discussion table rather than through media outlets.
These negotiations follow previous rounds that began on April 12, marking the highest-level contact between Tehran and Washington since the latter withdrew from a landmark agreement in 2018.
IRNA