The US, UK and more than 40 other countries have agreed to co-ordinate investigations into suspected war crimes in Ukraine, shortly after what Kyiv said was a Russian missile strike that killed civilians far from front lines.
The nations - which also includes EU states, Canada, Mexico and Australia - signed the political declaration at a conference in The Hague, the headquarters of the International Criminal Court.
It came as Volodymyr Zelensky accused Russia of committing an “open act of terrorism” with a strike on an office block that has killed more than 20 and injuring 90 others.
The Russian missiles struck the city of Vinnytsia, which sits southwest of Kyiv and has become a a hub for humanitarian aid.
Officials said they hit an office building, damaged nearby residential blocks and setting parked cars on fire.
“Every day Russia is destroying the civilian population, killing Ukrainian children, directing missiles at civilian objects,” Mr Zelensky wrote on Telegram after the strike.