Zelensky spoke hours before a Kremlin-sponsored three-day ceasefire, coinciding with the 80th anniversary of the World War II defeat of Nazi Germany, went into effect at midnight Moscow time.
There were no immediate reports of military activity from either side. Ukraine’s air force reported that Russian aircraft had targeted northeastern Sumy region with guided air bombs about an hour before the deadline.
“Ukraine’s proposal to cease strikes and establish at least a 30-day ceasefire remains in force. We are not withdrawing this proposal, which could give diplomacy a chance,” Zelensky said in his nightly video address.
Russia, he said, had made no response to the 30-day offer except for new strikes.
“This clearly and obviously demonstrates to everyone who the source of the war is,” the Ukrainian president added.
Zelensky also appeared to acknowledge the numerous drone attacks that have been targeting Russian sites, including the city of Moscow, as the World War Two commemorations approached.
“It is absolutely fair that Russian skies, the skies of the aggressor, are also not calm today, in a mirror-like way,” he said.
Moscow mayor Sergei Sobyanin, in a series of posts on the Telegram messaging app over a five-hour period, said 14 drones headed for the capital had been repelled or destroyed.
The US proposed the 30-day ceasefire in March and Ukraine agreed. Russia has said such a measure could only be introduced after mechanisms to enforce and uphold it are put in place.
Russian foreign ministry spokeswoman Maria Zakharova said Russia had observed a separate 30-day moratorium on attacks on energy sites and also observed a ceasefire to coincide with Orthodox Easter last month.
“Russia has never been opposed to a ceasefire. All the more so, we have done this twice,” Zakharova said in a comment posted on the foreign ministry’s website.
She expressed surprise at remarks from US envoy Keith Kellogg that Putin may be obstructing a comprehensive ceasefire.
“The only obstacle to the ceasefire is Kyiv, which violates agreements and is unwilling to seriously discuss the terms of a long-term ceasefire,” Zakharova said.