"This is a historic decision that will lead to historic accountability," he said in a nightly video address.
The real number of deported children could be much higher than 16,000, he said, and added that their deportations constituted a policy of 'state evil' "which starts exactly with the top official of this state."
The International Criminal Court (ICC) on Friday issued an arrest warrant against Putin, accusing him of the war crime of illegal deportation of children from Ukraine. The court also issued a warrant for Maria Lvova-Belova, Russia's Commissioner for Children's Rights, on the same charges.