TALKS between Iran and the United States over Tehran’s nuclear programme are “in a very crucial” stage, the head of the United Nations nuclear watchdog said on Thursday.

The comments by Rafael Mariano Grossi, of the International Atomic Energy Agency, while on a visit to Tehran included an acknowledgement that his agency likely would be key in verifying Iranian compliance should a deal be reached. 

The two sides will meet again in Rome on Saturday for a new round of talks, after last weekend’s first meeting in Oman.

US President Donald Trump has repeatedly threatened to attack Iran’s nuclear programme if a deal isn’t reached, but said on Thursday: “I’m not in a rush to do it because I think that Iran has a chance to have a great country and to live happily without death.” 

Iranian officials warn they could pursue a nuclear weapon using a stockpile of uranium enriched to near weapons-grade levels.

Mr Grossi arrived in Iran on Wednesday night and met Iranian Foreign Minister Abbas Araghchi before meeting Mohammad Eslami, the head of the Atomic Energy Organisation of Iran, on Thursday.

Mr Grossi said: “We know that we are in a very crucial, I would say, stage of this important negotiation.

“There is a possibility of a good outcome. Nothing is guaranteed. We need to make sure that we put all of the elements in place in order to get to this agreement.”

Mr Eslami said Iran expected the IAEA to “maintain impartiality and act professionally.”

Mr Grossi’s visit also coincided with Saudi Arabia’s Defence Minister Prince Khalid bin Salman, visiting Tehran as the highest-ranking official from the kingdom to visit Iran since the two countries reached a Chinese-brokered detente in 2023. 

The Saudi Press Agency said the prince’s trip would include “a number of meetings to discuss bilateral relations between the two countries and issues of common interest,” without elaborating.