DUBAI, United Arab Emirates (AP) — Talks between Iran and the United States over Tehran’s rapidly advancing nuclear program are “in a very crucial” stage, the head of the United Nations’ nuclear watchdog said Thursday while on a visit to the Islamic Republic.

The comments by Rafael Mariano Grossi of the International Atomic Energy Agency in Tehran included an acknowledgment his agency likely would be key in verifying compliance by Iran should a deal be reached. Iran and the U.S. will meet again Saturday in Rome for a new round of talks after last weekend’s first meeting in Oman.

Grossi’s visit also coincided with Saudi Arabia’s defense 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-mediated detente in 2023. That’s as Saudi Arabia tries to end its decadelong war against the Iranian-backed Houthi rebels in Yemen — even as a new, intense campaign of U.S. airstrikes targets them.

The stakes of the negotiations Saturday and the wider geopolitical tensions in the Mideast couldn’t be higher, particularly as the Israel-Hamas war rages on in the Gaza Strip.