Ukraine's Prosecutor General Andrii Kostin and the Registrar of the Hague-based International Criminal Court (ICC) Peter Lewis signed an agreement on opening the ICC's office in Ukraine on March 23.
Kostin called the document "another step towards ensuring full responsibility for international crimes," according to his office's report.
"This is just the beginning, but a good one," Kostin said. "I am convinced that we will not stop until all those guilty of international crimes committed against Ukraine are brought to justice, including the top military and political leadership of Russia's criminal regime."
The prosecutor general added he hoped for further cooperation with the ICC in the investigation and prosecution of Russian crimes against Ukraine. "I firmly believe our joint efforts will help build a fairer world."
The ICC issued arrest warrants on March 17 for Russian dictator Putin and Maria Lvova-Belova, the Russian official overseeing the forced deportations of more than 16,000 Ukrainian children to Russia.
The ICC asserts that there are "reasonable grounds to believe" Putin holds direct accountability for supervising the deportations and that he neglected to exert authority over Russian soldiers and civilians executing the crime across occupied Ukrainian regions from the onset of Russia's all-out war against Ukraine.
All 123 countries that are members of the ICC and have ratified the Rome Statute, which establishes crimes falling within the jurisdiction of the court, are now obliged to cooperate with the court's demand to arrest Putin.
Russia withdrew from the ICC in 2016 following criticism of Russia's illegal annexation of Crimea.
Ukraine signed the Rome Statute back in 2000 but never ratified it, although it became one of the country's international obligations after the ratification of the Association Agreement with the European Union in 2017.
However, the Rome Statute allows a state to recognize the ICC's jurisdiction in certain cases even without ratifying it. Ukraine did it with cases regarding the Revolution of Dignity in 2014 and cases on crimes against humanity and war crimes committed on its territory in 2015.
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