Grossi said last week while in Ukraine that he was working on a compromise security plan for the site and warned of increased military activity around it.

"Grossi will visit Kaliningrad on Wednesday as part of his ongoing consultations aimed at ensuring the protection of Ukraine's Zaporizhzhia Nuclear Power Plant during the military conflict," the International Atomic Energy Agency spokesman told AFP on Monday.

There are persistent fears over the safety of the plant in the southern Ukrainian region of Zaporizhzhia, where there has been frequent shelling since Russian troops invaded last year.

Grossi is to meet a "Russian interdepartmental delegation" on Wednesday, Russia's ambassador to the UN in Vienna Mikhail Ulyanov told Russian news agencies.

Ulyanov added that "declaring that a protection regime at the plant has been established" was "still a long way off".

Kyiv and Moscow have accused each other of shelling the plant, increasing fears of a disaster.

Grossi said last week after visiting the plant that his team had previously focused on the possibility of establishing a security zone around the plant, but "now the concept is evolving".

His team is now focusing on the protection of the plant itself rather than "on territorial aspects which pose certain problems," Grossi had said.

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