Russian President Vladimir Putin announced a temporary Easter ceasefire in Ukraine starting Saturday, citing humanitarian reasons, as Russia and Ukraine swapped hundreds of captured soldiers in the largest exchange since Moscow’s full-scale invasion started over three years ago.

According to the Kremlin, the ceasefire will last from 6 p.m. Moscow time (1500 GMT) on Saturday to midnight (2100 GMT) following Easter Sunday.

“We assume that the Ukrainian side will follow our example. At the same time, our troops must be ready to repel possible violations of the truce and provocations from the enemy, any of its aggressive actions,” Putin said at a meeting with Chief of the General Staff Valery Gerasimov, in a video shared by the Kremlin’s Press Service.

Ukrainian President Volodymyr Zelenskyy called the ceasefire “another attempt by Putin to play with human lives.” He wrote on X that “air raid alerts are spreading across Ukraine,” and “Shahed drones in our skies reveal Putin’s true attitude toward Easter and toward human life.”

In response to the ceasefire announcement, Ukrainian Foreign Minister Andrii Sybiha said that Kyiv had in March “agreed unconditionally to the U.S. proposal of a full interim ceasefire for 30 days,” which Russia rejected.

“Putin has now made statements about his alleged readiness for a ceasefire. 30 hours instead of 30 days,” Sybiha continued, writing on X. “Unfortunately, we have had a long history of his statements not matching his actions.”

The two sides meanwhile exchanged hundreds of POWs on Saturday. Russia’s Ministry of Defense said that 246 Russian service members were returned from territory controlled by Kyiv, and that “as a gesture of goodwill” 31 wounded Ukrainian POWs were transferred in exchange for 15 wounded Russian soldiers in need of urgent medical care.

Zelenskyy said that 277 Ukrainian “warriors” have returned home from Russian captivity.

Both sides thanked the United Arab Emirates for their mediation.

Putin’s ceasefire announcement came after U.S. President Donald Trump on Friday said negotiations between Ukraine and Russia are “coming to a head” and insisted that neither side is “playing” him in his push to end the grinding three-year war.

Trump spoke shortly after Secretary of State Marco Rubio warned that the U.S. may “move on” from trying to secure a Russia-Ukraine peace deal if there is no progress in the coming days, after months of efforts have failed to bring an end to the fighting.

In January 2023, Putin had ordered his forces in Ukraine to observe a unilateral, 36-hour cease-fire for Orthodox Christmas. Zelenskyy had dismissed it as playing for time to prepare additional attacks.

Russia’s Defense Ministry said Saturday its forces pushed Ukrainian troops from the village of Oleshnya, one of their last remaining footholds in Russia’s Kursk region where the Ukrainians staged a surprise incursion last year. Gerasimov said Saturday in a report to Putin, quoted by Russian state media, that Russia had retaken nearly all of the territory from Ukrainian forces.