Grossi holds Zaporizhzhia safety zone talks with Ukraine and Russia

In a media briefing Grossi told reporters: "Getting an agreement today would have been nice, but you can imagine that these are very complex issues that require perhaps a bit more than one meeting but we are already working on the very concrete aspects, that would be required to have the zone being established."

He said that he had met many people, including ministers, presidents and prime ministers during his trip and he said it was clear that "above differences that do exist, there is a conviction that the establishment of the zone is indispensable".

"Let's be clear - this nuclear power plant is being shelled, So you need to protect it in some way and we have the means, the technical knowledge, as the IAEA, to know what would need to be done and how to do it. So this process has started. I have, of course, indicated that this is not a negotiation of a treaty or something that could be afforded the luxury of weeks and months, and meetings and preparatory meetings. We have to decide on it urgently, as soon as possible. And I hope I will be able to do that."

Grossi said that he planned to travel to Ukraine in the near future, and Russia afterwards, as he seeks to get agreement on the form the safety and security zone would take as well as how it would be implemented and how it could be enforced.

Asked if he was referring to Russia and Ukraine when he said there was a recognition that a safety zone was indispensable, he said: "I think they know it’s indispensable but I would never speak for them. The mere fact that the two foreign ministers are sitting down with me and listening to our ideas - I think it’s a good indicator that there is a very strong solid base for this thing to happen."

The Zaporizhzhia nuclear power plant is Europe’s largest, with six reactors. It has been occupied by Russian forces since early March, although it continues to be operated by its Ukrainian staff.

After months of trying, Grossi led an IAEA inspection mission to the plant at the start of the month. Two IAEA experts have stayed at the plant since then and he said the plan was for the IAEA to enlarge the mission in the coming days. He said the inspectors had access to the entire plant and he said that the agency had more than 50 years of experience and said it was "very difficult, if not impossible to hide things from experienced inspectors". He said that he was confident the mission was working well "within, of course, the difficult circumstances".