"They are bragging that they can destroy with nuclear weapons not only a certain country but the entire planet," Zelensky said in a live video message to the forum on the 31st day of the Russian military assault against his country.
When Ukraine dismantled its nuclear stockpile in the 1990s it was given "security assurances from the most powerful countries in the world", including Russia, he said in comments translated into English for the conference.
"But these assurances did not become guarantees. And in fact, one of the countries supposed to give one of the greatest security promise started to work against Ukraine and this is the ultimate manifestation of injustice," Zelensky added.
