Ukraine's president has asked Pope Francis for help in securing the release of prisoners of war held by Russia and by Russia-backed separatist fighters in eastern Ukraine.
Volodymyr Zelenskiy made the request after a meeting with the pontiff at the Vatican on February 8.
"[The pope] does everything possible to achieve peace and harmony throughout the world," Zelenskiy said in a tweet after their meeting.
"I asked for help with the release of Ukrainians captured in Donbas, Crimea, and Russia," he said.
Russia annexed the Black Sea peninsula of Crimea in March 2014. A month later, fighting broke out in eastern Ukraine in a conflict that has killed more than 13,000 people and displaced more than 1 million.
Since being elected in May 2019, Zelenskiy has overseen two major swaps of prisoners with Russia and the separatist fighters it backs in eastern Ukraine.
The 83-year-old head of the Roman Catholic Church has on several occasions voiced hope for an end to the conflict.
Francis offered a prayer ahead of the key summit involving Zelenskiy and Russian President Vladimir Putin in Paris on December 9. Francis also called for peace in eastern Ukraine in his Christmas message on December 25.
The overwhelming majority of observant Ukrainians are Orthodox Christian; only a small percentage considers itself Roman Catholic.
However, Greek, or Eastern Rite Catholics, are the second-largest Christian denomination in the country and recognize the pope as its spiritual leader.
During the photo session of the meeting, which was open to reporters, Francis gave Zelenskiy a medal of St. Martin of Tours and said he hoped the saint "will protect your people from war."
Zelenskiy arrived in Italy on February 7, when he met with Italian Prime Minister Giuseppe Conte.
Talks in Rome were reported to focus on Vitaliy Markiv, a Ukrainian National Guardsman sentenced in 2019 by an Italian court to 24 years in prison for his role in the deaths of an Italian photojournalist and his translator during fighting near the eastern Ukrainian city of Slovyansk in 2014.