"The supplies of western tanks must outpace another invasion of Russian tanks," Zelenskiy said.
"The world must make faster than Russia makes its new moves."
Almost 11 months since Russia invaded its neighbour, Moscow's forces hold swathes of Ukraine's east and south. The battlefield momentum has been with Kyiv for months, but Moscow has expended huge resources, trying to advance in the east.
At the forum, he was asked whether he was worried about his own personal security after his interior minister was killed in a helicopter crash earlier on Wednesday. He said he was not worried.
Before he delivered his address, Zelenskiy asked the forum's participants to take part in a minute of silence to remember the 14 people killed in the helicopter crash. They included the minister, other senior officials, the crew and a child.
He accused Russia of exporting "terror," pointing to a Russian missile attack that destroyed an apartment building and killed at least 45 people. Moscow has blamed that civilian attack on Ukrainian air defences.
