British Prime Minister Boris Johnson said on Wednesday that he believed the actions of Russian President Vladimir Putin towards Ukraine already qualified as a war crime.
The office of the prosecutor of the International Criminal Court on Monday said it would seek court approval to open an investigation into alleged war crimes in Ukraine.
"What we have seen already from Vladimir Putin's regime in the use of the munitions that they have already been dropping on innocent civilians ... in my view already fully qualifies as a war crime," Johnson told parliament.
Fierce fighting and Russian bombardment since the invasion began last week have killed dozens in Ukraine and sparked a refugee crisis. Strikes have hit hospitals, schools and homes.
The most intensive bombardment has struck Kharkiv, a city of 1.5 million people in the east, whose centre has been turned into a bombed-out wasteland of ruined buildings and debris.
On Tuesday, Johnson said the shelling of Kharkiv by Russian forces was an atrocity reminiscent of the attacks on Sarajevo in the 1990s.
(Reporting by William James, Writing by Kylie MacLellan. Editing by Andrew MacAskill and Michael Holden)
