STRASBOURG, France, June 26, 2025 (BSS/AFP) - Ukrainian President Volodymyr Zelensky on Wednesday signed an accord with pan-European rights body the Council of Europe for establishing a special tribunal to try top officials responsible for Russia's invasion of Ukraine.

The court would prosecute the "crime of aggression" in the invasion, which Russia launched in February 2022, and could, in theory, try senior figures up to President Vladimir Putin.

"We need to show clearly aggression leads to punishment and we must make it happen together, all of Europe," said Zelensky after signing the accord with Council of Europe secretary general Alain Berset.

"There is still a long way to go. Justice takes time but it must happen," he added, saying the accord is a "real chance to bring justice for the crime of aggression".

"Every war criminal must know there will be justice and that includes Russia," said Zelensky.

Berset said the next step to set up the tribunal, which the Council of Europe hopes could start work next year, would be an enlarged agreement to "allow the widest possible number of countries to join, to support, and to help manage the tribunal".

It has not yet been decided where the tribunal would be based.

"International law must apply to all, with no exceptions and no double standards," said Berset.

This is the first time such a tribunal has been set up under the aegis of the Council of Europe, the continent's top rights body.

The 46-member Council of Europe is not part of the EU and members include key non-EU European states such as Turkey, the UK and Ukraine. Russia was expelled in the wake of its invasion of Ukraine.

Ukraine and its supporters want to see justice served for Russia's all-out invasion in 2022 and European foreign ministers endorsed the creation of the tribunal in a meeting in Lviv in western Ukraine on May 9.

The International Criminal Court (ICC) in The Hague has already issued arrest warrants for Putin over the abduction of Ukrainian children and four of his top commanders for targeting civilians.

But the ICC does not have the jurisdiction to prosecute Russia for the more fundamental decision to launch the invasion -- otherwise known as the "crime of aggression".

According to the Council of Europe, the tribunal will be set up within the framework of the body "with the mandate to prosecute senior leaders for the crime of aggression against Ukraine".

It said the tribunal "fills the gap" created by the "jurisdictional limitations" of the ICC.