STRASBOURG, France, June 26, 2025 (BSS/AFP) - Ukrainian President Volodymyr Zelensky on Wednesday said close ties between Europe and the United States under Donald Trump were key to ensuring Kyiv defeated the Russian invasion, as he urged a trial for President Vladimir Putin.

Zelensky signed an accord with the Council of Europe to set up a special tribunal to try top officials over Russia's invasion of Ukraine, as he made his first visit since the start of the conflict to the France-based rights body.

But after a face-to-face meeting with Trump earlier the day at the NATO summit in The Hague, Zelensky made an impassioned call for close ties between Europe and the US president.

"We need a strong connection with him (Trump)," Zelensky, who had a public spat with the American leader in the Oval Office earlier this year, told the Parliamentary Assembly of the Council of Europe.

"We need unity between Europe and the United States and we will prevail," Zelensky said, adding: "We need unity in Europe first of all."

The special tribunal would prosecute the "crime of aggression" in the full-scale invasion, which Russia launched in February 2022, and could, in theory, try senior figures up to 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".

"It will take strong political and legal courage to make sure every Russian war criminal faces justice, including Putin," Zelensky said.

- 'No double standards' -

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 but Zelensky said The Hague would be "perfect".

"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.