The Pope, meeting the Ukrainian leader for the second time in his two-month-old papacy, also discussed "the urgent need for a just and lasting peace," the Vatican said in a statement.
Zelenskiy and Leo held talks in Castel Gandolfo, a small Italian hill town not far from Rome, where the Pope is having a two-week holiday.
Zelenskiy said on X that holding talks with Russia in the Vatican would be "entirely possible, with the goal of stopping Russian aggression and achieving a stable, lasting, and genuine peace".
But he said Russia had rejected such proposals, "as it has turned down all other peace initiatives".
Russian officials have told Reuters in the past that they did not see the Vatican as a serious venue for talks because it is surrounded by NATO military alliance member Italy which has supported Ukraine.
The Ukrainian leader is in Italy to attend a conference on July 10-11 dedicated to Ukraine's recovery and long-term reconstruction following Russia's invasion.
The Vatican did not say how long the meeting between Leo and Zelenskiy lasted.
It released video showing Leo, the first US-born pontiff, asking Zelenskiy "How are things going?" in English as they sat in a large room together.
Leo, who has made appealing for peace in world conflicts a major theme of his young papacy, previously met Zelenskiy at the Vatican on May 18.
The Pope also held a phone call with Russian President Vladimir Putin on June 4, during which the Vatican said Leo had asked Putin to take concrete steps to end Russia's three-year war on Ukraine.
US President Donald Trump suggested in May that Leo had offered to host Ukraine-Russia peace talks although the pontiff did not discuss it publicly at the time.
Russian forces targeted Ukraine with 728 drones early on Wednesday, Ukrainian authorities said.
Ukraine's military downed almost all the drones but some of the six hypersonic missiles launched by Russia had caused unspecified damage, air force spokesman Yurii Ihnat said on Ukrainian television.
Officials reported one person killed by drone debris in western Ukraine.
Russia's defence ministry said it had struck military airfields.
Closer to the battle zone, eight people were reported killed by drones and guided bombs in the Ukrainian-held part of the frontline Donetsk region.
Trump said on Tuesday he was considering supporting a bill that would impose steep sanctions on Russia, including 500 per cent tariffs on countries that buy Russian oil, gas, uranium and other exports.
When asked by a reporter what action he would take against Putin, Trump said: "I wouldn't tell you. We want to have a little surprise."
7°C