THE HAGUE, March 18 (AFP) - The International Criminal Court on Friday (Mar 17) announced an arrest warrant for Russian President Vladimir Putin on the war crime accusation of unlawfully deporting Ukrainian children.

The Hague-based ICC said it had also issued a warrant against Maria Lvova-Belova, Russia's presidential commissioner for children's rights, on similar charges.

The Kremlin dismissed the orders as "void". Russia is not a party to the ICC so it was unclear if or how Putin could ever be extradited.

War-battered Ukraine welcomed the ICC announcement, with the nation's chief prosecutor saying the "historic" warrant for Putin was "just the beginning".

The court's shock notice came hours after other news with potential to significantly impact Russia's war on Ukraine, including a Moscow visit from Chinese leader Xi Jinping and more fighter jets for Kyiv's forces.

More than 16,000 Ukrainian children have been deported to Russia since the Feb 24, 2022 invasion, according to Kyiv, with many allegedly placed in institutions and foster homes.

The warrants, issued after an application by ICC prosecutor Karim Khan, were "for the alleged war crimes of deportation of children from Ukrainian occupied territories into the Russian Federation" since the invasion, he said.

ICC President Piotr Hofmanski added "the execution (of the warrants) depends on international cooperation".

The arrest warrant for Putin - a sitting head of state of a UN Security Council member - is an unprecedented step for the International Criminal Court.

Set up in 2002, the ICC is a court of last resort for the world's worst crimes, when countries cannot or will not prosecute suspects.

Prosecutor Khan launched an investigation into alleged war crimes and crimes against humanity in Ukraine just days after Russia's invasion.