"Russian troops have no heavy weapons either on the territory of the station or in areas around it. There are only guard units," the ministry said in a statement.

Pointing to accusations that Russian forces have been shelling Ukrainian positions from the territory of the station, the ministry said Kyiv was planning a "provocation" during a visit to Ukraine by UN chief Antonio Guterres that would see Moscow "accused of creating a man-made disaster at the plant".

It said Ukraine was deploying forces in the area and planned to launch artillery strikes on the plant from the city of Nikopol on Friday, when Guterres is due to visit Odessa.

"The blame for the consequences (of the strikes) will be placed on the Russian armed forces," it said.

Russian forces took control of the Zaporizhzhia plant in southern Ukraine in March, shortly after moving into the country.

The plant is the largest of its kind in Europe and uncertainty surrounding it has fuelled fears of a nuclear accident to rival the Chernobyl disaster in 1986.

NATO Secretary General Jens Stoltenberg said Wednesday that it was "urgent" to allow the International Atomic Energy Agency to inspect the plant and for Russian forces to withdraw.

He said Moscow's control of the plant "raises the risks of a nuclear accident or incident".

Stoltenberg also accused Russia of using "the ground around the nuclear power plant as a staging area, as a platform, to launch artillery attacks on Ukrainian forces".