Iran and the US held indirect talks under Omani mediation, announced the Iranian Foreign Ministry spokesman, Nasser Kanaani.
Kanaani announced that mediators are also negotiating the issue of exchanging prisoners if Washington showed "seriousness and goodwill."
Earlier, Iranian Supreme Leader Ali Khamenei expressed his support for an agreement on the country's nuclear program with the West but added that "the existing infrastructure of the nuclear industry should not be touched."
He urged Iranian officials to cooperate with the International Atomic Energy Agency (IAEA), calling on the officials not to yield to the Agency's "excessive and false demands”. He said that a law passed by Iran's parliament in 2020 had to be respected.
Kanaani said the government was "serious" in reaching an agreement following Khamenei’s orders and within the framework of the parliament law to secure national interests.
He claimed that "Iran's government has never left the negotiation table and has shown its readiness to conduct serious and substantive negotiations to reach a conclusion" on reviving the Joint Comprehensive Plan of Action (JCPOA).
Kanaani confirmed reports about talks between Iran and the US through Oman mediation in the past few weeks, claiming the Muscat talks were not secret but an opportunity to defend Iran's national interests.
"We welcomed the mediation proposal put forward by senior Omani officials several weeks ago and exchanged messages with the other party, with the aim of activating the 'sanctions removal' talks," he said.
"We have never stopped the diplomatic processes."
Last week, a well-informed senior European source told Asharq Al-Awsat that a return to the agreement in the form proposed a year ago was "no longer possible," noting that any deal must be negotiated from the outset.
Two European diplomatic sources also told Asharq Al-Awsat that the Omani mediation is related to issues outside the nuclear agreement.
One of the diplomats said that the US has other outstanding issues they are discussing through Omani officials.
Axios website revealed that indirect negotiations occurred between the chief Iranian negotiator, Ali Bagheri Kani, and the White House Middle East Coordinator, Brett McGurk, last month in Muscat about concluding an interim agreement.
In the past few days, Washington and Tehran denied media reports that the two sides had reached an interim agreement on reviving the 2015 nuclear deal, which includes the release of US detainees and Iran reducing uranium enrichment by 60 percent in exchange for the release of frozen Iranian assets in South Korea, Iraq, and the World Bank.
The US special envoy to Iran, Robert Malley, and the Iranian ambassador to the United Nations in New York, Saeed Irvani, held several meetings.
On Saturday, Iranian lawmaker Mojtaba Tavanger confirmed the meetings, but the US obstructions failed the prisoner exchange deal.
"America is trying to get more concessions from Iran in nuclear matters in exchange for releasing frozen funds, a policy violating the law and contradictory to Iran's interests," Tavangar added.
Former US President Donald Trump withdrew from the nuclear deal in 2018 to modify Iran's regional behavior and its expansion of ballistic missile activities.
On Friday, the White House described press reports of an interim agreement as "false and misleading."
Iran's mission to the UN also cast doubt on the report: "Our comment is the same as the White House comment."
At least three Iranian-US nationals are being held in Iran, including businessman Siamak Namazi, who was arrested in October 2015 and sentenced to ten years on espionage charges.
In 2022, Iran said that dozens of its citizens were detained in the US, some of whom were accused of circumventing US sanctions, including exporting equipment used in the Iranian weapons industry.