Ukraine's prosecutor general told the AFP news agency during a visit to Brussels that Russian "war crimes" had become a "pattern of conduct ... a policy which is orchestrated from the very top leadership" during the war. 

"Russia must be defeated on the battlefield and in the courtroom," Andriy Kostin told AFP. 

He said investigators had logged around 123,000 war crime cases in total. He said that 511 suspects had been identified, of which 357 could be brought to justice in his team's estimation. 

He said Ukraine had already convicted 81 Russian war criminals, with 17 of them present in court for a trial. 

Even though most of the verdicts were handed down in absentia, he argued they were nevertheless important for victims or their relatives to see the issue addressed in court. 

While calling for international prosecution of Russian officials, Ukraine has also said it will continue to investigate and prosecute alleged war crimes itself. 

The most ambitious arrest warrant issued since the invasion targets Russian President Vladimir Putin himself. The International Criminal Court issued the warrant last March, but critics question whether it will ever lead to a trial.

Neither Russia nor Ukraine are full ICC Rome Statute signatories, but Ukraine has authorized the court to investigate potential Russian war crimes on its territory since the 2014 annexation of Crimea and war in the Donbas region.