Foreign ministers from the Group of Seven industrialized nations have agreed to impose tougher sanctions on Russia if it does not stop its assault on Ukraine, and demanded in particular that Moscow halt attacks in the vicinity of nuclear power plants.

The meeting Friday in Brussels, which Japanese Foreign Minister Yoshimasa Hayashi joined online, took place as Russia's attacks on the Zaporizhzhia nuclear power plant in southern Ukraine, the largest in Europe, briefly fueled fears of a devastating nuclear catastrophe.

"Any armed attack on and threat against nuclear facilities devoted to peaceful purposes constitutes a violation of the principles of international law," said the ministers from Britain, Canada, France, Germany, Italy, Japan and the United States, plus the European Union, in a joint statement issued after the talks.