UN inspectors said Wednesday they would seek to establish a permanent presence at a Russian-held plant in southern Ukraine to avoid "a nuclear accident" at the facility on the frontline of the fighting.
The 14-strong team from the International Atomic Energy Agency (IAEA) is expected to arrive at the Zaporizhzhia nuclear plant, which lies inside Russian-held territory, on Thursday.
"We are preparing for the real work which begins tomorrow," he said. "We are going to try to establish a permanent presence for the agency."
Fresh shelling struck the town next to Europe's largest atomic facility on Wednesday, with the fate of the plant on the banks of the Dnipro River stoking global concern.
"The Russian army is shelling Energodar," local military official Evhen Yevtushenko said on Wednesday morning, of the town next to the plant which had a pre-war population of 50,000 people.
Both sides have repeatedly traded blame over attacks in the area.
One of the shells hit Energodar's city council, Mayor Dmytro Orlov wrote on Telegram, posting pictures of the damaged building with a hole punched into the side.
- 'Explicit safety guarantees' -
Although Zaporizhzhia is normally about a two-hour drive from the plant, it was not immediately clear how the IAEA team would reach the site which would involve crossing the frontline to enter Russian-held areas.
But Grossi said his team had received "explicit" safety guarantees from both sides for their visit which would last "a few days".
"These are very complex operations," he said.
The plant has been occupied by Russian troops since March and Ukraine has accused Russia of deploying hundreds of soldiers and storing ammunition there.
Kyiv has insisted the team access the plant via Ukrainian-held territory.
"Sadly, Russia is not stopping its provocations precisely in the direction the mission needs to travel to reach the plant," President Volodymyr Zelensky said late Tuesday after meeting Grossi.
The situation was "extremely menacing", he said, accusing the Russians of "continuing bombardments" and calling for "an immediate and total demilitarisation" of the Zaporizhzhia nuclear plant.
In Moscow, the Russian defence ministry accused Kyiv of "continued provocations aimed at disrupting the work of the IAEA mission" saying it had shelled the area around the plant on Tuesday hitting a building containing "the solid radioactive waste processing complex".
- Counteroffensive in the south -
Meanwhile, intensive fighting raged across the nearby southern region of Kherson where Ukraine began a counteroffensive on Monday.
Most of the region and its provincial capital of the same name were seized by Russian forces at the start of the invasion six months ago.
With the war in the eastern Donbas region largely stalled, analysts have said for weeks that combat is likely to shift south to break the stalemate before winter comes.
In its morning update, the president's office in Kyiv said "fighting continued throughout the night" in Kherson, and that one person had been killed and two injured in an overnight bombing in the Mykolaiv area.
But the Russian defence ministry said Kyiv's attempts to advance its counteroffensive had "failed" with Ukrainian forces suffering "significant losses and were driven back by Russian troops".
As Ukraine presses its offensive, the White House said Wednesday that there would be an announcement in the coming days on additional military aid for Kyiv, on top of $13 billion already pledged by Washington.
EU foreign ministers on Wednesday agreed to suspend a 2007 visa facilitation deal with Russia, which will make it more difficult and longer for Russian nationals to get visas.
EU's foreign policy chief Josep Borrell said ministers had agreed that relations with Moscow "cannot be business as usual".
Zelensky, who has called for a total ban on EU tourist visas for Russians, said Wednesday that Russian society must pay the price for the war.
"I think it is humiliating for Europe when it is considered simply as one big boutique or restaurant," he said in his daily address to the nation. "Europe is a territory of values first of all, not primitive consumption."
And earlier in the day, Russian energy giant Gazprom suspended gas deliveries to Germany, citing maintenance issues in the latest of a series of supply stoppages that have fuelled an energy crisis in Europe.
The move comes as European countries have faced soaring energy prices since Russia invaded Ukraine in late February and subsequently curbed its gas deliveries to the region.