KYIV — Ukraine's President Volodymyr Zelensky said on Saturday his forces would observe a 30-hour Easter truce announced by Russia set to last until midnight on Sunday.

However, just hours after the order was meant to have come into effect, air-raid sirens sounded in Ukraine's capital Kyiv and Zelensky accused Russia of having maintained its artillery fire and assaults on the front line.

Also on Saturday, Russia and Ukraine held a large exchange of prisoners, each side saying they had handed back more than 240 captured fighters.

The order to halt all combat over the Easter weekend followed a United States announcement that it could abandon peace talks within days unless Moscow and Kyiv showed they were serious about negotiating.

"Today from 1800 (1500 GMT Saturday) to midnight Sunday (2100 GMT Sunday), the Russian side announces an Easter truce," Russian President Vladimir Putin said in televised comments during a meeting with the Russian chief of the general staff.

Zelensky responded by saying Ukraine would follow suit, and proposed extending the truce beyond Sunday, saying "30 days could give peace a chance".

"In general, as of Easter morning, we can say that the Russian army is trying to create a general impression of a ceasefire, but in some places it does not abandon individual attempts to advance and inflict losses on Ukraine," Zelensky said on social media.

Meanwhile, Russia's Defense Ministry said on Sunday that Ukraine had broken the Easter ceasefire more than a thousand times, inflicting damages to infrastructure and causing civilian deaths.

The ministry said Ukrainian forces had shot at Russian positions 444 times while it had counted more than 900 Ukrainian drone attacks.

Agencies via Xinhua