He said: “That is why today, within the framework of the negotiating process mediated by the American side, we received Russia’s agreement to conduct a prisoner exchange in the format of 1,000 for 1,000. A ceasefire regime must also be established on May 9, 10, and 11. Ukraine is consistently working to bring its people home from Russian captivity. I have instructed our team to promptly prepare everything necessary for the exchange.”

Zelensky concluded by thanking Trump for his efforts and urging Washington to hold Russia to its end of the bargain.

Kremlin aide Yuri Ushakov told Russian media that Russia agreed to the proposal, adding that it came after a conversation between Putin and Trump.

The ceasefire will be the first mutual ceasefire since hostilities began on Feb. 24, 2022. Russia has announced unilateral ceasefires coinciding with Orthodox Easter, and a mutual cessation of strikes on energy infrastructure was abided by for one month earlier this year, but no comprehensive ceasefires have yet been reached.

Trump’s announcement marks an end to a high-stakes game of chicken being played between Russia and Ukraine in recent days. Ukraine’s repeated long-range drone attacks have increasingly targeted Moscow, feeding Russian fears that Ukraine would attack the capital in the middle of Russia’s annual Victory Day parade, commemorating its victory over Nazi Germany. Ukraine had refused to take the option off the table, leading to a specific Russian threat that it would hit sensitive non-military targets in central Kyiv if such an attack were carried out during the parade.

Ukraine responded to a Russian unilateral ceasefire announcement covering the Victory Day period by announcing its own beginning several days before, saying it would abide by Russia’s ceasefire if Moscow abided by that one. Wary of giving off the impression that its actions were being dictated by Kyiv, Russia continued attacks against Ukraine unabated, leading Zelensky to announce that the ceasefire was off.

Pleas from other countries fell on deaf ears, with Zelensky issuing cryptic warnings for foreigners to stay away from the Victory Day parade. Several heads of state were due to be in attendance, including the Prime Minister of European Union member Slovakia, Robert Fico.

The fact that only Trump was able to get Ukraine to agree marks the president’s biggest accomplishment in his peacemaking efforts between Moscow and Kyiv, if it holds.

Victory Day is one of the most important national holidays in modern Russia, featuring a grandiose parade to celebrate and commemorate its defeat of Hitler’s Wehrmacht in 1945. The war between Nazi Germany and the Soviet Union remains the largest single war in history, with more troops engaged on the Eastern Front than every other front of World War II combined. An estimated 27 million Soviets died in the war, by far the largest share of casualties of the war.

The commemoration of the Soviet Union’s role in the “Great Patriotic War” is sacrosanct in Russia, while in Ukraine, views are more split. The Ukrainian government’s cultural reforms since the invasion have further complicated matters, as the widely-celebrated nationalist Ukrainian Insurgent Army primarily fought the Soviet Union, even allying with the Nazis against them at times.