In an appeal to Belarus and its people during a media conference at NATO headquarters, Michel said: "You have the choice not to follow Russia's destructive action. You have the choice not to take part in this needless tragedy against your neighbours in Ukraine."

Belarus, a Russian ally that borders Ukraine to the north, has welcomed tens of thousands of Russian troops in its territory in the wake of mass pro-democracy protests that erupted in 2020 after autocratic leader Alexander Lukashenko claimed victory in skewed elections.

Belarus is permitting those troops to pour across its border into Ukraine and to using their positions to hammer Ukrainian forces with artillery, according to Ukraine's government.

Lukashenko on Thursday said that Russian President Vladimir Putin had called him to inform him of his military operation against Ukraine. He said that Belarus's own national forces "are not taking part in this operation".