Belarus leader Alexander Lukashenko says Belarusian troops are not currently taking part in the Russian invasion - but could do if needed.
Russian convoys have entered Ukraine from Belarus. Moscow has had troops in Belarus for weeks, ostensibly for military exercises.
"I say again: our troops are not there. But if it is necessary, if it is necessary for Belarus and Russia, they will," Lukashenko said in remarks reported by the state news agency Belta.
Belarus is a long-time ally of Russia. Analysts describe the small country as Russia's "client state".