The Special Tribunal for the Crime of Aggression against Ukraine (STCAU, ) is an ad hoc international criminal tribunal aimed at prosecuting individuals responsible for the Russian invasion of Ukraine under the legal concept of crimes of aggression, as a complement to the existing International Criminal Court investigation in Ukraine.
An agreement between the Council of Europe and Ukraine to establish the tribunal was signed on 25 June 2025 in Strasbourg. The agreement sets out the conditions for establishing the tribunal and includes its statute in an annex. , the tribunal had not yet been established.
Background In 2022 and 2023, several international bodies announced their support for establishing a tribunal for prosecuting the crime of aggression against Ukraine, including the Council of Europe, the European Commission, the NATO Parliamentary Assembly and the European Parliament.
Proposals In April 2022 the Parliamentary Assembly of the Council of Europe (PACE) called for an ad hoc international criminal tribunal. In September 2022, the Council of Europe proposed to create a tribunal that would have a mandate to "investigate and prosecute the crime of aggression" committed by "the political and military leadership of the Russian Federation." Under the Council of Europe's proposal, the tribunal should be located in Strasbourg, "apply the definition of the crime of aggression" established in customary international law and "have the power to issue international arrest warrants and not be limited by State immunity or the immunity of heads of State and government and other State officials."
The government of Ukraine called for the establishment of such a tribunal.
In November 2022 the NATO Parliamentary Assembly designated the Russian Federation as a terrorist organization and called upon the international community to "take collective action towards the establishment of an international tribunal to prosecute the crime of aggression committed by Russia with its war against Ukraine." The European Commission said that the European Union (EU) would work to establish an ad hoc criminal tribunal to investigate and prosecute Russia's crime of aggression.E.U. proposes special tribunal to investigate Russian crimes in Ukraine In the same month the European Parliament also designated Russia as a state sponsor of terrorism, citing attacks against civilians, war crimes, and atrocities.
On 19 January 2023, the European Parliament called for the creation of an international tribunal to carry out investigations and prosecutions for Russian and Belarusian responsibility for the crime of aggression, complementary to the International Criminal Court investigation in Ukraine. The vote passed with 472 votes in favour, 19 against and 33 abstentions.
Core group In late February 2023, Ukrainian foreign minister Dmytro Kuleba stated that a "core group" for creating the tribunal existed, including representation from Guatemala. In March 2025, the core group held its fourteenth and final meeting, finishing the technical preparation of drafts of three documents: a bilateral agreement between Ukraine and the Council of Europe (CoE) to establish the tribunal; the tribunal's statutes; and a management document. Hosting of the tribunal was likely to be in The Hague. It was expected that trials in absentia for prosecuting Russian leaders while they remained in office would be excluded. Planned formalisation of the agreements was scheduled for signing by Ukrainian authorities on 9 May 2025, to be followed by a vote by the Parliamentary Assembly of the Council of Europe (PACE).
International Centre for the Prosecution of the Crime of Aggression Following European Union (EU) supported negotiations in March 2023, and given that neither Ukraine nor Russia had at that timeIn the meantime, Ukraine ratified them https://treaties.un.org/pages/ViewDetails.aspx?src=TREATY&mtdsg_no=XVIII-10-b&chapter=18&clang=_en ratified the 2010 ICC Kampala Amendments to the Rome Statute that added the crime of aggression alongside war crimes, crimes against humanity and genocide to ICC jurisdiction, the International Centre for the Prosecution of the Crime of Aggression (ICPA) was created in July 2023 by Eurojust to gather evidence and coordinate judicial actions related to the Russian invasion of Ukraine as a crime of aggression. The creation of the centre was seen as a first step towards creating a tribunal. Aims of the ICPA would include supporting exchange of evidence and coordination of investigative and prosecutorial strategies. An EU joint investigation team including Ukrainian, Lithuanian, Latvia, Estonian, Polish and Romanian representatives participated in establishing the ICPA.
The creation of the ICPA was the first institutional action to investigate a specific crime of aggression since World War II. The Kampala Amendments giving the ICC jurisdiction for crimes of aggression became effective in 2018, with an exception in Article 15bis (5) of the updated Statute that excludes jurisdiction when the crime is done on the territory of, or by nationals of, a state that is not an ICC member state. Ukraine was not a member state at the time of the full-scale invasion, having not yet ratified the Rome Statute, nor were Russia and Belarus. The ICC declared its willingness to support and cooperate with the ICPA.
Steps towards creation On 9 May 2025, representatives of 35 states and the Council of Europe (CoE) met in Lviv and, with support from High Representative of the European Union Kaja Kallas and EU Commissioner Michael McGrath, agreed to proceed with creating the proposed tribunal, stating that legal instruments were technically complete. A followup meeting on 13–14 May in Luxembourg by the Committee of Ministers of the Council of Europe was scheduled for further formal steps in creating the tribunal.
On 25 June 2025, the statute of the Special Tribunal was officially published as an annex to a formal legal agreement between the Council of Europe and Ukraine.
By early December 2025, according to Kateryna Rashevska of the Ukrainian NGO Regional Center for Human Rights, the EU had provided million in funding for the tribunal, The Hague had been chosen as the location of the tribunal, and the practical creation of the tribunal was expected "by 2026 or 2027". Veronika Sentsov-Velch, the director of the Ukrainian section of Amnesty International, predicted that the tribunal's initial investigations would focus on "a group of approximately 20 high-ranking Russian officials".
In November 2025, Lithuania expressed its intention to support the Tribunal by signing a document called the Enlarged Partial Agreement. By April 2026, 17 European countries had signed the agreement, as had Costa Rica.
By 15 May 2026, the date of a Committee of Ministers session in Chișinău, altogether 34 CoE members states, Costa Rica, Australia and the EU had signed the Enlarged Partial Agreement. At the meeting, Secretary General of the Council of Europe, Alain Berset, expressed his wish for the political commitment to be followed by funding and other practical steps towards creating the Tribunal. Dutch foreign minister Tom Berendsen stated that the Netherlands had agreed to "host the initial phase" of the Tribunal in The Hague.
Statute of the Tribunal The Tribunal has jurisdiction to prosecute individuals bearing the greatest responsibility for the crime of aggression committed against Ukraine, applying its own Statute, the Rules of Procedure and Evidence, relevant international treaties, customary international law and, where necessary, the criminal law of Ukraine.
Article 1 contains no time limitation. This authorises the Tribunal to prosecute not only those responsible for the 2022 invasion but also those responsible for the illegal invasion and annexation of Crimea in 2014. This contrasts with the Registry of Damage Caused by the Aggression of the Russian Federation against Ukraine, created by the Council of Europe, which is limited to damages since 24 February 2022.
Like the International Criminal Court, the Tribunal guarantees fundamental procedural safeguards, including the right to a fair trial, the right not to be tried twice for the same conduct, the presumption of innocence, and the right to remain silent.
Organisation of the Tribunal
The Special Tribunal consists of three main organs: the Chambers, the Office of the Prosecutor, and the Registry.
Chambers The Chambers are composed of:
One judge acting as the Pre-Trial Judge, who reviews the indictment and can issue orders and warrants.
Three judges sitting in the Trial Chamber, who conduct the trial, rule on the evidence, and render judgments and sentences.
Five judges in the Appeals Chamber, who decide on appeals against convictions, acquittals or sentences.
Judges are elected to a roster of 15 for staggered nine-year terms. They must be of high moral character and fully independent. No two judges may be nationals of the same State.
The President of the Tribunal is elected by the judges for a renewable three-year term and presides over the Appeals Chamber. The Pre-Trial Judge, unlike the ICC's Pre-Trial Chamber of three judges,Article 39 of the Rome Statute resembles the single judge formation used by the European Court of Human Rights for filtering admissibility.
Office of the Prosecutor The Office of the Prosecutor is an independent organ of the Tribunal, responsible for conducting impartial investigations and prosecutions of those who bear the greatest responsibility for the crime of aggression against Ukraine.
The Prosecutor must be a person of high moral character, demonstrating the highest level of professional competence, with substantial experience in conducting complex investigations and prosecutions of serious criminal cases.
The Prosecutor is assisted by at least one Deputy Prosecutor and other staff as necessary to perform duties effectively and efficiently. Both the Prosecutor and Deputy Prosecutors are elected by secret ballot by an absolute majority of the Management Committee members, based on a shortlist prepared by an independent advisory panel.
The Prosecutor and Deputies cannot seek or receive instructions from any government or authority, and may not engage in any other professional occupation while in office.
To ensure impartiality, any person investigated or prosecuted can request the disqualification of the Prosecutor or Deputy Prosecutors on grounds of conflict of interest or lack of independence; such requests are decided by the Appeals Chamber.
Investigations are initiated by the Prosecutor General of Ukraine "referring" any criminal cases, information or evidence to the Prosecutor of the Special Tribunal.
Registry The Registry is the principal administrative organ of the Tribunal and is responsible for its overall administration and servicing.
The Registry is headed by the Registrar, who must be a person of high moral character with extensive experience in managing international criminal justice institutions. The Registrar is elected by the judges sitting in plenary session and formally appointed by the Secretary General of the Council of Europe for a renewable four-year term.
The Registry includes several specialised units:
A Victims and Witnesses Unit, which provides protective measures, security arrangements, counselling, and other assistance for witnesses and victims who are at risk due to their testimony. It also organises collective representation of victims before the Tribunal.
A Detention Unit, which manages the conditions of detention of suspects and accused persons.
An independent Defence Unit, which upholds the rights of the defence by maintaining a list of defence counsel, providing legal research, evidence collection support, advice, and appearing before the Tribunal on specific issues if needed.