An international office tasked with investigating Russia's war in Ukraine opened Monday in The Hague, in a move Kiev deemed "truly historic" toward the eventual creation of a tribunal to try Russian leaders.

The International Centre for the Prosecution of the War Crime Against Ukraine (ICPA) brings together prosecutors from Kiev, the European Union, the United States and the International Criminal Court.

The office's mission is to investigate and gather evidence, and is seen as a first step before the establishment of a special tribunal to try senior Russian officials for the outbreak of war in Ukraine, a demand of Kiev.

Ukrainian authorities are reviewing more than 93,207 war crimes reports and <> suspects have been charged in local courts.

Senior officials who committed crimes could be tried at the International Criminal Court in The Hague, which has already requested the arrest of Russian President Vladimir Putin.

A number of senior officials held a press conference at the headquarters of the European Union's judicial agency in The Hague, Eurojust reported in a statement.

They include Ukrainian Prosecutor General Andriy Kostin, ICC Prosecutor Karim Khan, US Deputy Attorney General Kenneth Bulait, and European Commissioner for Justice Didier Reynders.

Ukrainian Prosecutor General Andriy Kostin said that the opening of the new office in The Hague will lead to "holding Moscow's leaders accountable for the war crime of aggression due to the invasion of Ukraine by their army."

Kostin said the new center would gather evidence on potential cases against Russian military and political leaders responsible for the war.

"If crimes of aggression had not been committed, there would have been no further 93,<> incidents of war crimes, and this day is proof that the establishment of a special court is now inevitable," he said.

U.S. Attorney General Kenneth Bullet told the news conference that Washington was "proud to stand by its European partners" in prosecuting the perpetrators of Russia's "illegal war of aggression against the people of Ukraine."

He added that the United States also supports a tribunal that looks into aggression.

European Commissioner for Justice Didier Reynders said Monday's opening of the office showed Kiev's allies "will stand with Ukraine for as long as necessary", adding: "We cannot tolerate flagrant violation of the prohibition against the use of force."

Calls for the establishment of a special war court in Ukraine intensified, as the ICC has jurisdiction only for war crimes and crimes against humanity committed on Ukrainian territory.

In March, the Hague-based court issued an arrest warrant for Russian President Vladimir Putin for the supposed forcible deportation of Ukrainian children.


Special Prosecutor

Kiev has been pushing for a special court since hundreds of bodies were discovered after Russian troops withdrew in April 2022 from the city of Bucha, near the Ukrainian capital.

International support for this demand continues to grow, and in February the European Commission announced the establishment of the International Centre for the Prosecution of the Crime of Aggression against Ukraine.

Brussels said the centre's aim was to "prosecute those responsible for the invasion" of Ukraine.

U.S. involvement has added weight to the request for a court, although Washington still refuses to become a member of the ICC.

During a visit to The Hague in June, US Attorney General Merrick Garland appointed a special war crimes prosecutor, Jessica Kim, as a representative at the International Centre for the Prosecution of the Crime of Aggression against Ukraine, but a complex question remains over how such a court will work, and Ukraine supports a UN General Assembly resolution.

But some Western backers fear that the initiative will not have enough international support, calling instead for the creation of a hybrid court composed of Ukrainian and other national judges.

The International Criminal Court, set up in 2002 to try the world's most serious atrocities, does not have the authority to rule on what Ukraine calls Moscow's "crimes of aggression" as Russia is not a signatory to the Rome Statute.

But shortly after the war began, the court opened an investigation into crimes committed in that country, and in March issued an arrest warrant for the Russian president.

In response, Russian authorities placed ICC prosecutor Karim Khan on the "wanted" list.

Moscow, in turn, opened a criminal investigation against Karim Khan and three judges at the court, and according to the investigation, Khan is accused of "initiating criminal prosecutions against a person known to be innocent" and "preparing an attack on the representative of a foreign state."