"We regret that in your report... the source of the shelling is not directly named," Russian Ambassador Vasily Nebenzya told a Security Council session attended virtually by Rafael Grossi, head of the International Atomic Energy Agency (IAEA).

"We do understand your position as an international regulator, but in the current situation it's very important to call things by their name," he said.

The IAEA in a report released earlier Tuesday called for a demilitarized zone to be set up outside Europe's largest nuclear plant, which was seized by Russian troops during their invasion of Ukraine.

Both sides have blamed each other for shelling, which took place again Tuesday despite the watchdog's recommendations.

"If the provocations by the Kyiv regime continue, there is no guarantee that there won't be serious consequences, and the responsibility for that lies fully with Kyiv and its Western backers and all other members of Security Council," Nebenzya said.

Western powers voiced dismay at his remarks, saying that the fundamental issue was Russia's invasion of and occupation of the plant.

"Despite Russia's song and dance here today to avoid acknowledging responsibility for its actions, Russia has no right to expose the world to unnecessary risk and the possibility of the nuclear catastrophe," senior US diplomat Jeffrey DeLaurentis told the session.

Ukraine also hit back, saying that there were no issues at the plant until Russia seized it.

"The world not only deserves but needs the representatives of the IAEA to force Russia to demilitarize the territory of the (nuclear power plant) and return full control over the plant to Ukraine," said Sergiy Kyslytsya, Ukraine's ambassador.

Grossi, speaking after a visit to Zaporizhzhia, said that nuclear inspectors were more accustomed to traveling after a disaster such as in Chernobyl and Fukushima.

"In this case, had the historical, ethical imperative to prevent something from happening," Grossi said.

"We are playing with fire and something very, very catastrophic could take place."