On May 17, 2025, Deputy Chairman of the Russian Security Council Dmitry Medvedev made a strong statement warning “all enemies of Russia” against issuing ultimatums during the negotiations. According to him, unsuccessful attempts to reach an agreement could provoke “an even more terrible stage of the war” with the involvement of new participants and the use of new weapons.

"Failure of negotiations could lead to the beginning of a more terrible stage of war with new weapons and participants," Medvedev said.

The talks in Istanbul, the first direct contact between the parties since March 2022, were mediated by Turkey. The Russian delegation was led by presidential aide Vladimir Medinsky, and the Ukrainian by Defense Minister Rustem Umerov. According to Reuters, Russia proposed terms including neutral status for Ukraine, recognition of Crimea and four regions as part of the Russian Federation, and an end to Western arms supplies to Kyiv. These proposals were rejected by Ukraine as “unrealistic.” However, the parties agreed to prepare for a “1000 for 1000” prisoner exchange scheduled for May 21 on the Belarusian-Ukrainian border.