U.N. chief Antonio Guterres on Thursday called for military activity around Ukraine's Zaporizhzhia nuclear power complex to end as Moscow and Kyiv blamed each other for a renewed shelling and the U.N. Security Council met to discuss the situation.

Russia seized Europe's largest nuclear power plant in March after invading Ukraine on Feb. 24. The plant is still run by its Ukrainian technicians. Ukraine's Energoatom said the area was struck five times on Thursday, including near the site where radioactive materials are stored.

Russia's defence ministry said in a statement that the Ukrainian shelling had partly damaged a thermal power plant and splash pools that form part of the reactors' cooling systems.

Guterres urged the withdrawal of military personnel and equipment and for no more forces or equipment to be deployed. He called for Russia and Ukraine not to target the facilities or surrounding area.

"The facility must not be used as part of any military operation. Instead, urgent agreement is needed at a technical level on a safe perimeter of demilitarization to ensure the safety of the area," Guterres said in a statement.

Ukraine's President Volodymyr Zelenskiy accused Russia of using the nuclear power plant "to threaten the entire world."

"Only a full withdrawal of the Russians from the territory of the Zaporizhzhia nuclear power station and the restoration of full Ukrainian control of the situation around the station can guarantee a resumption of nuclear security for all of Europe," Zelenskiy said in his nightly video address.

The United States backed the call for a demilitarized zone around the plant, U.S. under-secretary for arms control and international security, Bonnie Jenkins, told the U.N. Security Council on Thursday. She said a visit by the International Atomic Energy Agency (IAEA) "cannot wait any longer."

'NUCLEAR CATASTROPHE'

IAEA chief Rafael Grossi briefed the 15-member Security Council on Thursday at the request of Russia. Grossi said that he was ready to lead an IAEA mission to Zaporizhzhia and called on Russia and Ukraine to cooperate so the inspectors could travel as soon as possible.

"The IAEA has been ready to perform such a mission since June when we were ready to go. But unfortunately, due to political factors and other considerations, it was not possible," Grossi told the council, adding that all military action around the plant needed to stop.

Russia's U.N. Ambassador Vassily Nebenzia said the trip agreed between Russia and the IAEA in June was cancelled by U.N. security officials.

"We believe it justified for IAEA representatives to go to the Zaporizhzhia nuclear power plant as quickly as possible and possibly even before the end of August," Nebenzia told the Security Council.

He said the world was being pushed "to the brink of nuclear catastrope, comparable in scale with Chernobyl."

U.N. spokesman Stephane Dujarric has said the United Nations was committed to doing everything possible to get the IAEA technicians to Zaporizhzhia.

"There's a war going on, and we're talking about nuclear power plant in the middle of a battlefield," Dujarric told reporters on Thursday. "I think we can think of at least two or three pages' worth of hurdles."