Russia, which invaded Ukraine four years ago, has launched deadly strikes on its neighbour's power grid, repeatedly cutting supply to nuclear power plants.

The resolution submitted by Canada and the Netherlands to the International Atomic Energy Agency (IAEA) board passed with 20 votes in favour, four against and 10 abstentions, one diplomat told AFP.

Those who voted against against were China, Russia, Niger and "for the first time" the United States, the diplomat added.

Washington deemed it "an unnecessary resolution that does not help achieve peace between Ukraine and Russia," Howard Solomon, Washington's representative to the IAEA said in his statement to the board during the debate.

The resolution noted with "concern" IAEA head Rafael Grossi's reporting that attacks on Ukraine's power grid have created a "heightened risks" at nuclear power plants.

"Attacks targeting Ukraine's energy infrastructure critical for the off-site power supply of nuclear power plants... represent a direct threat to nuclear safety and security," the resolution reads.

It also asked Grossi to propose "additional measures to prevent a nuclear accident if additional risks arise".

Ukraine's nuclear power plants, including Europe's biggest, Zaporizhzhia, occupied by Russian forces since March 2022, have been repeatedly affected by fighting, including suffering a loss of off-site power.

Zaporizhzhia's six reactors have been shut down since the occupation. But the site still needs electricity to maintain its cooling and security systems.

Moscow and Kyiv repeatedly accuse each other of risking a nuclear catastrophe by attacking the plant.