In a separate development, U.S. Secretary of State Marco Rubio and Russian Foreign Minister Sergey Lavrov spoke by phone on May 17 to discuss the outcome of the Istanbul meeting and the broader contours of the cease-fire. Rubio said in a statement on social media that he conveyed Trump’s message—“the death and destruction must stop”—while urging the Russian side to end hostilities.

“The U.S. has presented a strong peace plan and we welcome the Prisoner of War exchange agreement reached in Istanbul,” Rubio wrote. “Let’s not miss this huge opportunity. The time for ending this war is now.”

Lavrov noted the United States’ “positive role” in getting Ukraine to return to the negotiating table and confirmed Moscow’s willingness to continue diplomatic engagement, the Russian Foreign Ministry said, per Russian state media outlet TASS.

“The conversation also touched on several other international and regional issues. The sides exchanged opinions on developing Russia-US relations,” it added.

Zelenskyy expressed frustration with the stalled talks and reiterated Ukraine’s call for a full, unconditional cease-fire.

“Ukraine has long been offering this—a full and unconditional ceasefire in order to save lives. Russia retains nothing but the ability to continue killing,” Zelenskyy said in a post on social media on May 17.

He accused Russian forces of deliberately targeting civilians, citing a drone strike on a bus evacuating residents from the Sumy region that killed nine people.

“All the deceased were civilians,” he said. “This was a deliberate killing of civilians.”

Russia’s Defense Ministry said its forces struck a military site in Sumy but did not mention any civilian casualties.

Zelenskyy also called for harsher sanctions on Moscow if it refuses to pursue serious peace efforts.

“Without tougher sanctions, without stronger pressure, Russia will not seek real diplomacy,” he wrote on social media.

Trump, speaking to Fox News in an interview recorded during his recent trip to Abu Dhabi, said he believed a negotiated peace was within reach.

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