The United States and Iran went into detail about a potential nuclear deal on Saturday at their third consecutive round of talks, hoping to strike an accord that would ease regional tensions.

US special envoy Steve Witkoff and Iranian Foreign Minister Abbas Araghchi again led the talks, which this time included a technical-level meeting between experts from both sides.

The discussions via mediators in Muscat, the Omani capital, lasted more than seven hours, according to Iranian officials and state media.

"The expert and technical talks between the two delegations reached the stage of minute details about mutual demands and expectations," said a state TV reporter.

Oman's Foreign Minister Badr Albusaidi, who mediated the talks, said a fourth round is expected next Saturday.

"Talks will continue next week with a further high-level meeting provisionally scheduled for May 3," Albusaidi posted on X, adding that "core principles, objectives and technical concerns were all addressed" at the latest meetings in Muscat.

The discussions are aimed at striking a new deal that would stop Iran from developing nuclear weapons – an objective Tehran denies pursuing – in return for relief from crippling sanctions.

US President Donald Trump pulled out of an earlier multilateral nuclear deal during his first term in office. The US and Israel have repeatedly threatened Iran with military strikes. (AFP)