On November 16, 2023, at a meeting in Berlin of representatives of the “Core Group” of countries that support the establishment of the Special Tribunal for the Crime of Aggression against Ukraine, the representative of Switzerland, Ambassador Franz Perez, director of the Office of International Law of the Federal Department of Foreign Affairs, announced the accession of his country to the "Core Group". Switzerland became the 39th Core Group country to establish a Special Tribunal for the Crime of Aggression.

Switzerland is convinced that the crime of aggression committed against Ukraine should not go unpunished.

Participation in the Core Group complements Switzerland's support for national and international efforts to prosecute and bring to justice those responsible for all international crimes committed in Ukraine.