Russian President Vladimir Putin declared an “Easter truce” in the war in Ukraine on Saturday, saying that the Russian side will cease military action from 6 p.m. local Saturday night until midnight April 21.

Putin said he assumes that “the Ukrainian side will follow our example,” according to a statement on the Kremlin’s Telegram channel. But he also says Russia will respond to “violations of the truce and provocations” by Ukraine, the statement said.

In a statement Saturday, Ukrainian President Volodymyr Zelenskyy did not say whether or not Ukraine would agree to the truce, but called the proposal “yet another attempt by Putin to play with human lives” and said there were still Russian attacks being launched in the hour before the Russian ceasefire was meant to take effect.

Zelenskyy later said there has not been a complete ceasefire of Russian military action, saying, “according to the Commander-in-Chief reports, Russian assault operations continue on several frontline sectors, and Russian artillery fire has not subsided.”

He added that Ukraine will engage in a full ceasefire if Russia does, and touched on the 30-day ceasefire proposal turned down by Russia.

“If a complete ceasefire truly takes hold, Ukraine proposes extending it beyond the Easter day of April 20,” Zelenskyy said. “That is what will reveal Russia’s true intentions – because 30 hours is enough to make headlines, but not for genuine confidence-building measures. Thirty days could give peace a chance.”

The proposed truce comes as U.S. officials, including Secretary of State Marco Rubio, continued holding talks in Paris this week to discuss ending the war in Ukraine. Rubio said the talks were “productive” but asserted that the U.S. was willing to move on from the negotiations if they didn’t yield results.

“We need to figure out here, now within a matter of days, whether this is doable in the short term, because if it’s not, then I think we’re just going to move on,” Rubio said on the tarmac as he left France early Friday morning.

Later, at the White House, President Donald Trump echoed Rubio’s assertion — saying that the U.S. would make a determination “very shortly.”

In the wake of Rubio’s public comments, Moscow signaled it was in no hurry to strike a deal.

These developments also come as one potential indicator of progress — a 30-day ceasefire intended to pause strikes on energy infrastructure targets-has expired, with no word from Putin on whether Moscow will restart attacks on those targets.

Both Russia and Ukraine have accused each other of repeatedly violating the agreement, which was brokered by the Trump administration last month.

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.

This is a developing story. Check back for updates.

ABC News’ Oleksiy Pshemyskiy and Shannon Kingston contributed to this report.

The Associated Press contributed to this report.