Any attack on a nuclear plant is "suicidal", United Nations Secretary-General Antonio Guterres warned Monday after fresh shelling hit a huge atomic power complex in southern Ukraine.
Moscow and Kyiv blame each other for the latest strike at the Zaporizhzhia plant, Europe's largest nuclear power site, which has been under Russian control since the early days of the war.
The fighting on Friday at the plant has prompted the UN's nuclear watchdog, the International Atomic Energy Agency (IAEA) to warn of "the very real risk of a nuclear disaster".
At a press conference in Tokyo, Guterres condemned such attacks without saying either side was responsible.
"We support the IAEA on their efforts in relation to create the conditions of stabilization of that plant," he said.
"Any attack to a nuclear plant is a suicidal thing. I hope that those attacks will end, and at the same time I hope that the IAEA will be able to access the plant."
His comments followed a visit to Hiroshima over the weekend, where Guterres gave a speech to mark the 77th anniversary of the world's first nuclear bomb attack.
Ukrainian President Volodymyr Zelenskiy accused Russia of waging "nuclear terror" that warranted more international sanctions, this time on Moscow's nuclear sector.
"There is no such nation in the world that could feel safe when a terrorist state fires at a nuclear plant," Zelenskiy said in a televised address on Sunday.
Russian forces captured the plant in southeastern Ukraine in early March but it is still run by Ukrainian technicians.
The Russian-installed authority of the area said Ukrainian forces hit the site with a multiple rocket launcher, damaging administrative buildings and an area near a storage facility.