He called for global rules to curb the use of artificial intelligence in weapons while describing breakneck innovation in the military use of drones.
Zelenskiy also accused Russian President Vladimir Putin of seeking to expand his war beyond Ukraine.
"We are now living through the most destructive arms race in history," Zelenskiy said at the UN General Assembly on Wednesday.
"Ukraine is only the first and now Russian drones are already flying across Europe, and Russian operations are already spreading across countries, and Putin wants to continue this war by expanding it."
"Stopping Russia now is cheaper than wondering who will be the first to create a simple drone carrying a nuclear warhead," Zelenskiy told the 193-member assembly.
Zelenskiy said Ukraine had decided to begin exporting its weapons to allies.
"You don't need to start this race from scratch. We're ready to share what has already proven itself," he said, referring to defence production.
"We are ready to make our modern weapons become your modern security. We have decided to open up arms export. And these are powerful systems tested in a real war when every international institution failed," he said.
Zelenskiy's comments came a day after he met with US President Donald Trump, who expressed support for Ukraine's efforts and criticised Russia.
Trump said on Tuesday that Ukraine could retake all its occupied land from Russia in what would be an extraordinary battlefield reversal.
A Ukrainian drone attack on the Russian Black Sea naval base of Novorossiisk killed at least two civilians and injured three others, local authorities said on Wednesday.
The region's governor Veniamin Kondratyev denounced the "terrible attack" in broad daylight on the city centre.
"Five residential buildings, including apartment buildings, and a hotel building were damaged," he wrote on Telegram.
Russian authorities had earlier warned of a possible attack on the port by unmanned Ukrainian watercraft.
Meanwhile, former military chief Valerii Zaluzhnyi criticised Ukraine's failed cross-border offensive into Russia's Kursk region, saying the losses were unacceptably high.
"The price of these actions is unknown to me but it is obvious that it was too high," Zaluzhnyi, now Ukraine's ambassador to the United Kingdom, wrote in an article for the online outlet Dzerkalo Tyzhnia published on Wednesday.
He said Russian forces not only blocked a Ukrainian breakthrough but also gained tactical advantages after repelling the attack.
Ukrainian troops mounted a surprise push into Russia's Kursk border region in August 2024.
They were eventually driven back after months of fighting, aided by North Korean support for Russia.
Zelenskiy justified the operation as a way to gain leverage in possible future peace talks.
Zaluzhnyi argued the war has reached a state of prolonged deadlock, thanks to the heavy use of drones by both sides.
"It is practically impossible to break through defensive lines. Any troop concentration at the front or in the rear is detected (by drones), making surprise strikes for a breakthrough virtually impossible," he wrote.
Only rapid adoption of technological innovations such as artificial intelligence and autonomous weapons, he said, could shift the balance.
Zaluzhnyi led Ukraine's armed forces from July 2021 until February 2024.
After the unsuccessful Ukrainian counteroffensive in the summer of 2023, he warned in The Economist of a technological stalemate - a characterization that reportedly strained his already tense relationship with Zelenskiy.
Released from military service in early 2024, he became ambassador to the UK.
Polls suggest he would be a strong contender to unseat Zelenskiy if martial law was lifted and elections held.
with Reuters and DPA
