Iran and the United States started a new round of nuclear talks in Rome on Saturday to resolve their decades-long standoff over Tehran’s atomic aims, under the shadow of President Donald Trump’s threat to unleash military action if diplomacy fails.

Iran’s Foreign Minister Abbas Araqchi and Trump’s Middle East envoy Steve Witkoff will negotiate indirectly through an Omani official who will shuttle messages between the two sides, Iranian officials said, a week after a first round of indirect talks in Muscat that both sides described as constructive.

Araqchi and Witkoff interacted briefly at the end of the first round, but officials from the two countries have not held direct negotiations since 2015 under former US President Barack Obama.

Araqchi, in a meeting with his Italian counterpart ahead of the talks, said Iran had always been committed to diplomacy and called on “all parties involved in the talks to seize the opportunity to reach a reasonable and logical nuclear deal”.

“Such an agreement should respect Iran’s legitimate rights and lead to the lifting of unjust sanctions on the country while addressing any doubts about its nuclear work,” Araqchi was quoted as saying by Iranian state media.

He said in Moscow on Friday that Iran believes reaching an agreement on its nuclear programme with the US is possible as long as Washington is realistic.

“Rome becomes the capital of peace and dialogue,” Italian Foreign Minister Antonio Tajani wrote on X. “I encouraged (Araqchi) to follow the path of negotiation against nuclear arms. The hope of the Italian government is that all together may find a positive solution for the Middle East.”

Tehran has, however, sought to tamp down expectations of a quick deal, after some Iranian officials speculated that sanctions could be lifted soon. Iran’s utmost authority, Supreme Leader Ayatollah Ali Khamenei, said this week he was “neither overly optimistic nor pessimistic”.

For his part, Trump told reporters on Friday: “I’m for stopping Iran, very simply, from having a nuclear weapon. They can’t have a nuclear weapon. I want Iran to be great and prosperous and terrific.”