Thursday, Ukrainian President Volodymyr Zelensky accused Russia of "nuclear blackmail" for seizing the southern Ukrainian power facility at Zaporizhzhia.

Russia seized the facility in March, shortly after invading Ukraine, and on Wednesday, President Vladimir Putin ordered his government to assume control of it. The facility is the largest in Europe, and Ukrainian workers continue to operate it.

"(The) capturing of Zaporizhzhia nuclear power plant (stands) for nuclear blackmail and for exerting pressure on the world and on Ukraine," Zelensky said in a video presentation to the Lowy think tank in Sydney through a translator.

"You're not using the weapons, but you can still be blackmailing by not having the nuclear power plant working for the people - the people are not receiving the electricity."

Before the Russian invasion, the plant supplied around one-fifth of Ukraine's electricity.

Moscow and Kyiv each accuse the other of attacking the plant's territory, risking a nuclear disaster.

On Thursday evening, Rafael Grossi, the head of the U.N.'s nuclear watchdog, was set to hold negotiations in Kyiv over the creation of a safety zone surrounding the power plant.

In his speech, Zelenskiy encouraged Australia to help unite the international community in its response to Russia.

Next week, the United Nations General Assembly will decide whether to condemn Russia's annexation of Donetsk and Luhansk in eastern Ukraine, as well as Kherson and Zaporizhia in the south. Russia is advocating for a secret ballot vote on the matter.

"We must now correct our joint efforts in a way to make the vote at the General Assembly for this resolution as unanimous as possible," Zelenskiy stated.

He stated that Putin was analyzing the response to his illegal annexation measures, which were rejected by Kyiv and the West.

"If the world's response is weak then Russia will come up with a new escalation," Zelenskiy warned.