Regarding the ongoing nuclear negotiations between the United States and Iran, Grossi told AP that he has been in “constant contact” with the parties.

“They are negotiating, it’s not us, but it is obvious that the IAEA will have to be the guarantor of whichever agreement they come to,” he said.

While there continue to be major areas of contention between the two sides — particularly over uranium enrichment — Grossi said he is encouraged that they are negotiating directly, and he believes both sides are serious about reaching a deal.

“I think they both want an agreement, which doesn’t mean that it’s easy to get, but, simple and obvious as this may sound, having two sides that want an agreement is an enormous advantage,” he said. “In my long diplomatic career, I have participated in negotiations where it was not necessarily the case that the sides wanted an agreement.”

The US and Iran have held five rounds of nuclear talks since April 12 and are expected to meet again for negotiations aimed at reaching a new agreement. The two countries have been at odds over the level of uranium enrichment.