Switzerland on Thursday sent out official invitations to more than 160 delegations ahead of June's Ukraine peace conference.
The peace talks will take place on June 15-16 at the Bürgenstock resort on Lake Lucerne. Global leaders are expected in attendance.
Switzerland is organizing the meeting at Kiev's request, with the aim of developing a pathway to a lasting peace more than two years after the Russian invasion of Ukraine. Russia has already ruled out participation.
Discussions will be held on the basis of the peace plan Ukrainian President Volodymyr Zelensky presented to the United Nations in late 2022.
Kiev has demanded that the perpetrators of alleged war crimes in Ukraine be brought to justice. It is also seeking security and territorial guarantees.
In autumn 2022, Zelensky drew up 10 points that included the withdrawal of Russian troops, reconstruction and reparations, and the prosecution of war criminals.
Moscow, however, asserts Russia's claimed right to rule over its neighbour, arguing at most, the future of western Ukraine is unclear.
Ukraine has been resisting the Russian invasion since February 2022.
Zelensky has also been pleading for more support and ammunition from Western partners as Russian forces push hard at the front lines and target infrastructure, particularly power plants.