The Russian aggression against Ukraine has raised the need for accountability and international rule of law. Russia through committing the supreme international crime has deliberately violated basic international principles and norms such as state sovereignty and territorial integrity of Ukraine and the prohibition of the use of force. Member states of the United Nations drafted and agreed to create the International Criminal Court to punish the most serious crimes. The Kampala amendments of the Rome Statute on aggression, adopted a decade later, can be activated if the two states concerned have accepted ICC jurisdiction. Russia and Ukraine are not members of ICC, although the unilateral declarations of Ukraine accepting ICC jurisdiction can be exercised for war crimes, crimes against humanity and genocide committed in the territory of Ukraine. The lack of an international mechanism to punish the crime of aggression against Ukraine have triggered calls and actions to create a special tribunal with a limited focus on that crime, based on the development of international criminal law over the past eighty years. The EU recently agreed to establish an International Center for the prosecution of the crime of aggression – to preserve evidence and prepare the analysis of the evidence for the prosecution for future national or international trials – which is considered a first step in that direction. This research will analyze options to create either a special international tribunal or a hybrid tribunal to investigate whether Russia’s acts of violence in Ukraine constitute a crime of aggression and their prosecution. It will examine the legal basis of its establishment and functioning of the tribunal based on previous precedents, such as the International Military Tribunal (Nuremberg), or other specialized courts integrated in a national justice system with international judges – hybrid court. It will also explore the indispensable role of the United Nations in establishing such a tribunal and its implications in ending the conflict.
 
 Received: 13 January 2023 / Accepted: 17 March 2023 / Published: 20 March 2023