Russian forces have taken over the coal-fired Vuhlehirsk power plant in eastern Ukraine, an adviser to President Volodymyr Zelenskyy said on Wednesday, according to Reuters.

The announcement confirms an earlier claim by Russian-backed forces to have captured the plant, which is Ukraine's second biggest power plant.

"They achieved a tiny tactical advantage - they captured Vuhlehirsk," the adviser, Oleksiy Arestovych, said in an interview posted on YouTube.

Russia was undertaking a "massive redeployment" of troops to three southern regions, Arestovych added.

Earlier in the Ukraine invasion, Russian forces captured several nuclear power plants, beginning with Chernobyl, which was captured on February 24.

Russian troops left Chernobyl after weeks of occupation in late March.

After capturing Chernobyl, Russian forces also captured the Zaporizhzhia nuclear facility after hitting it with artillery fire, setting it ablaze.

There were also reports of artillery shells damaging a nuclear research facility in the city of Kharkiv, though there was no "radiological consequence".

Meanwile on Wednesday, US Secretary of State Antony Blinken said that he planned a phone conversation with Russian Foreign Minister Sergei Lavrov, the first between the two diplomats since before the start of the war.

The call would not be "a negotiation about Ukraine," Blinken said at a news conference, restating Washington's position that any talks on ending the war must be between Kyiv and Moscow.

Russia has received no formal request from Washington about a phone call between Blinken and Lavrov, TASS news agency reported.