Iranian Foreign Minister Abbas Araghchi and US Middle East envoy Steve Witkoff held a first round of talks on Saturday via Omani mediation in Muscat, marking the highest-level Iran-US nuclear negotiations since the collapse of a 2015 accord.

They agreed to meet again in seven days.

"We very much welcome this step, but we will be vigilant with our British and German friends and partners to ensure that any negotiations that may be undertaken are consistent with our security interests," Barrot said at a meeting of EU foreign ministers in Luxembourg.

Iran's foreign ministry said Sunday that talks with the US slated for next weekend would remain "indirect" with Omani mediation, and be focused solely on the nuclear issue and lifting of sanctions.