Pope Francis and President Hassan Rouhani held private talks at the Vatican on Tuesday.
Rouhani's visit to the Holy See marked the first meeting between a pope and an Iranian president since 1999.
Iran, which agreed to limit its nuclear activities in exchange for an end to economic sanctions, is eager to carve out a bigger role in mediating Middle East conflicts. Francis' papacy has been marked by mediation and conflict resolution.
The president is on a four-day European swing to boost Iran's image abroad as well as to rehabilitate economic ties with a continent that had been a major trade partner before sanctions.
"I ask you to pray for me," Rouhani told Francis after their 40-minute meeting, according to AP. He called the visit by a senior official of a Muslim country to the head of the Roman Catholic church "a real pleasure".
Francis thanked Rouhani for the visit and added, "I hope for peace." He gave the Iranian a medal depicting St. Martin helping a poor man, an act Francis called "a sign of unsolicited brotherhood."
Rouhani brought a gift of a handmade rug. He told the pope the red-toned carpet was made in the Iranian holy city of Qom.
