国際法学者や元ICC裁判官らが、侵略犯罪に関してICCの管轄権を補完する特別法廷の設置を諸国に呼びかける文書を公表している。
So to complement the actions now underway before the ICC, ICJ and ECtHR we propose the creation of a special tribunal with a limited focus on the crime of aggression, which cannot be addressed by the three other courts. The Special Tribunal for the Punishment of the Crime of Aggression against Ukraine can be set up with speed. During the second world war, nations met in London in 1942 to draft a resolution on German war crimes, which led, at the end of the conflict, to the creation of an International Military Tribunal and the Nuremberg trials.
To help beat back President Putin's heinous attempts to destroy peace in Europe, it is time for us to create such a Special Tribunal. By doing so we act in solidarity with Ukraine and its people, and signal our resolve that the crime of aggression will not be tolerated, and that we will leave no stone unturned in bringing to an end the terrible events we are now seeing, thereby ensuring that those who have unleashed such horrors are subject to personal accountability under the criminal law, so that justice can be done.
The Special Tribunal should be constituted – on the same principles that guided the allies in 1942 – to investigate the acts of violence by Russia in Ukraine and whether they constitute a crime of aggression. Countries should agree to grant jurisdiction arising under national criminal codes and general international law to a dedicated criminal tribunal, and confer on such a tribunal jurisdiction to investigate both the perpetrators of the crime of aggression and those who have materially contributed to or shaped the commission of that crime.
宣言には、諸国政府に向けた特別裁判所設置に関する宣言案が付属している。
The undersigned, representing the governments of []:
[...]
(3) Resolve, in a spirit of international solidarity, to grant jurisdiction arising under national criminal codes and general international law to a dedicated international criminal tribunal that should be established to investigate and prosecute individuals who have committed the crime of aggression in respect of the territory of Ukraine, including those who have materially influenced or shaped the commission of that crime;
【3月5日 AFP】ウクライナのドミトロ・クレバ（Dmytro Kuleba）外相は4日、英ロンドンの王立国際問題研究所（チャタムハウス、Chatham House）で開かれたイベントで、英国のゴードン・ブラウン（Gordon Brown）元首相や国際法専門家らが呼び掛けている特別法廷の設置を支持するとした。
【2023年2月10日 ウクライナ大統領府】ウクライナ大統領府高官によれば、侵略犯罪法廷設置のための「コア・グループ（Core Group）」が1月に発足し、20か国が参加していると表明された。
【2023年5月9日】コア・グループ共同声明が発表された。2023年夏に、ロシア侵略犯罪の訴追のための国際センター（International Center for the Prosecution of the Crime of Russian Aggression）がハーグで発足するという。5月19日、G7サミットは「ウクライナに関する共同声明」を発出し、同センターの設立を歓迎した。