Following the massive aerial barrage, Zelenskyy held a round of calls with allies, including Nato chief Mark Rutte, Finnish President Alexander Stubb and Norwegian Prime Minister Jonas Gahr Store.
Russia said it had only hit military targets during the attack.
Russia’s full-scale invasion has ravaged swathes of eastern and southern Ukraine, killing tens of thousands of soldiers and civilians.
The Ukrainian leader vowed his country would target Russia’s ability to fund the war and force Moscow to the negotiating table.
At least four people were killed in Kyiv, authorities said, and more than 40 people were wounded across the Zaporizhzhia, Odesa, Sumy, Cherkasy and Mykolaiv regions.
Drones, cruise missiles
Kyiv region resident Mark Sergeev and his family were sleeping when a missile hit their apartment in the middle of the night.
“I still can’t believe that the children are alive. It’s such a blessing from God. They were right under the roof when it hit them. The roof was torn off right above my eldest son’s bed,” the 35-year-old told AFP.
Anna, 26, said her flat was covered in broken glass after it was hit.
“I was in shock, so I didn’t hear much… But I heard a rocket flying for a long time, and then there was just an explosion and the windows shattered,” she said.
Zelenskyy posted photos of residential buildings in flames, with emergency services putting out fires and rescuing people from shattered buildings.
More victims could be uncovered in the debris, rescuers said. AFP reporters saw rescuers using heavy machinery to clear up the rubble from almost completely destroyed buildings.
Apart from residential buildings, a cardiology centre and a kindergarten were among the buildings hit across the country, Ukraine’s foreign ministry said.
Russia rained down 643 drones and rockets, including cruise missiles, across eastern, central and southern Ukraine, Ukraine’s General Staff said.

‘They will regret it’
Poland’s armed forces said on X that Warsaw had scrambled fighter jets in its airspace and put ground-based air defence systems on high alert.
In recent weeks, several European countries have accused Russia of violating their airspace with drones and fighter jets, in what Nato sees as a test of its resolve.
Russia has denied that it is responsible for the incursions or that it plans to attack any Nato nation.
In an address at the UN General Assembly in New York on Saturday, Moscow’s Foreign Minister Sergei Lavrov warned that “any aggression against my country will be met with a decisive response”.
Zelenskyy said Ukraine received a US-made Patriot air defence system from Israel, and two more were expected to arrive soon, after he returned from New York, where he also addressed the UN.
Kyiv and Moscow also said on Saturday that the Russian-occupied Zaporizhzhia nuclear power plant – Europe’s largest – had been off the grid for four days, stoking fears of a potential nuclear incident.
-Agence France-Presse