More than 3.3 million refugees have already fled Ukraine through its western border, with around 2 more million displaced inside the country.
"Every day of this war the Russian army does something that leaves me speechless. But then the next day it does something else that makes you feel the same way again," Zelenskiy said in a late night video address.
The eastern Donetsk region has faced the brunt of Russia's offensive since its assault on Kyiv failed weeks into the invasion launched on February 24.
Energoatom, operator of the Zaporizhzhia nuclear power plant in the south of the country, said on Saturday that parts of the facility had been "seriously damaged" by military strikes and one of its reactors was forced to shut down.
The meeting also comes a day after the head of NATO said it was "urgent" that the UN's atomic watchdog be allowed to inspect Ukraine's Zaporizhzhia nuclear power plant, where a Russian occupation has sparked concerns of a nuclear accident.
After ending weeks of resistance by the last Ukrainian fighters in the strategic southeastern city of Mariupol, Russia is waging a major offensive in Luhansk, one of two provinces in Donbas.
Ukrainian President Volodymyr Zelensky made a powerful appeal to the global business community at the annual meeting of the World Economic Forum in Davos on Sunday. He offered to the countries and businesses an attractive model for rebuilding
Incessant shelling has left Ukrainian forces defending ruins in Sievierodonetsk, but their refusal to withdraw is stalling a massive Russian offensive across the Donbas.
Zelensky expressed confidence in Ukraine's ability to reclaim territory, calling on the nation's allies to send more weapons. "We just need enough weapons to ensure all of this. Our partners have them."