"We are working on making it happen this fall," he said.
"Autumn is very soon, but there is still time to prepare for the summit and involve most of the world's countries."
Mr Zelenskyy and his team are working with allies to build broad support for the summit, which would endorse principles to underpin a settlement to end the war started by Russia's invasion almost 18 months ago.
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The summit would build on a 10-point plan outlined by Kyiv last autumn, which has been promoted by Mr Zelenskyy.
His vision for peace calls for the full restoration of Ukraine's territorial integrity and complete withdrawal of Russian troops, the protection of food and energy security, nuclear safety, the release of all prisoners, and other points.
No venue has yet been agreed on for the summit.
Ukrainian and western officials have said the summit would not include Russia.