The International Criminal Court (ICC) on Friday issued an arrest warrant for Russian President Vladimir Putin, alleging Moscow's forcible deportation of Ukrainian children is a war crime, as the Kremlin reacted with outrage.

Russia has not concealed a program under which it has brought thousands of Ukrainian children to Russia but presents it as a humanitarian campaign to protect orphans and children abandoned in the conflict zone.

Ukraine's President Volodymyr Zelenskiy said the move would lead to "historic accountability", adding that the deportations constituted a policy of "state evil which starts precisely with the top official of this state."

The announcement provoked a furious response from Moscow. Kremlin spokesperson Dmitry Peskov said Russia found the very questions raised by the ICC "outrageous and unacceptable", and that any decisions of the court were "null and void" with respect to Russia. Russia, like the United States and China, is not a member of the ICC.

"Yankees, hands off Putin!" wrote parliament Speaker Vyacheslav Volodin, a close ally of the president, on Telegram.

"We regard any attacks on the president of the Russian Federation as aggression against our country," he said.

The United States said there was "no doubt" Russia was committing war crimes in Ukraine. The court also issued a warrant for Maria Lvova-Belova, Russia's commissioner for children's rights, on the same charges.

Putin, only the third serving president to have been issued an arrest warrant by the ICC, is unlikely to end up in court any time soon. But the warrant means that he could be arrested and sent to The Hague if he travels to any ICC member states.

"This makes Putin a pariah. If he travels, he risks arrest. This never goes away. Russia cannot gain relief from sanctions without compliance with the warrants," said Stephen Rapp, former U.S. ambassador-at-large for war crimes.

Residents of the Russian capital expressed disbelief at the news. "Putin! Nobody will arrest him," a man who gave his name only as Daniil, 20, told Reuters.

Maxim said, "We will protect him - the people of Russia."

Moscow's forces have been accused of multiple abuses during Russia's year-old invasion of its neighbor Ukraine, including by a U.N.-mandated investigative body that this week described soldiers making children watch loved ones being raped.

Moscow has repeatedly denied accusations its forces have committed atrocities during the invasion, which it calls a special military operation.

ICC prosecutor Karim Khan began investigating possible war crimes, crimes against humanity and genocide in Ukraine a year ago. He said he was looking at alleged crimes against children and the targeting of civilian infrastructure.

News of the arrest warrant came ahead of a planned state visit to Moscow next week by Chinese President Xi Jinping which is likely to cement much closer ties between Russia and China just as relations between Moscow and the West hit new lows.

Beijing and Moscow struck a "no limits" partnership shortly before the invasion, and U.S. and European leaders have said they are concerned Beijing may send arms to Russia.

China has denied any such plan, criticizing Western weapon supplies to Ukraine, which will soon extend to fighter jets after Poland and Slovakia this week approved deliveries. The Kremlin said the jets would be destroyed and not change the course of the conflict.

China is keen to deflect Western criticism over Ukraine, but its close ties to Russia and its refusal to label Moscow’s war an invasion have fueled skepticism about the prospect that Beijing might act as a mediator in the conflict.

White House national security spokesperson John Kirby said on Friday the United States had deep concerns China might try to promote a ceasefire because that would not currently lead to a just and lasting peace between Ukraine and Russia.

Ukrainian forces continued on Friday to withstand Russian assaults on the ruined city of Bakhmut, the focal point for eight months of Russian attempts to advance through the industrial Donetsk region in eastern Ukraine bordering Russia.

Bakhmut has become Europe's bloodiest infantry battle since World War Two. Russian forces have captured the city's eastern part but have so far failed to encircle it.

The General Staff of Ukraine's armed forces said Russia had carried out 19 airstrikes and 26 rocket attacks on Friday.

Russian forces also conducted four air strikes on the frontline town of Avdiivka south of Bakhmut on Friday, Yermak, the Ukrainian presidential staff chief, wrote on Telegram. "The city is being shelled almost around the clock," he wrote.

Reuters could not immediately verify those battlefield reports.

Russia denies deliberately attacking civilians but says it has hit infrastructure to degrade Ukraine's military and remove what it says is a potential threat to its own security.

Ukraine and its allies accuse Moscow of an unprovoked war to grab territory from its pro-Western neighbor.

(Reuters)

Russian President Vladimir Putin. (Reuters)

International court issues warrant for Putin's arrest