"I met Zelensky today in Zaporizhzhia City and had a rich exchange on the protection of the Zaporizhzhia NPP (nuclear power plant) and its staff," Grossi wrote on Twitter.

"I reiterated the full support of the IAEA to Ukraine's nuclear facilities," he said, referring to the International Atomic Energy Agency which he heads.

Zaporizhzhia is home to Europe's largest nuclear power plant, which Russia captured a year ago.

Earlier on Monday Zelensky said he visited Ukrainian military positions in the Zaporizhzhia region.

"I am honoured to be here today, next to our military," Zelensky said on social media, posting a video of himself and Ukrainian servicemen.

"We will definitely win."

During the trip, the Ukrainian president visited a local command post and decorated policemen and servicemen, the presidency said in a statement.

Zelensky's visit to Zaporizhzhia came after he visited the southern region of Kherson last week as well as military positions in the eastern Donetsk region.