The papal trip to Lesbos, accompanied by the head of the Eastern Orthodox Church, is likely to pile pressure on European leaders already criticised for the deal with Turkey, which aims to defuse Europe's worst migration crisis since World War II by curbing the influx of people.
"The Greek government will welcome Pope Francis and the Ecumenical Patriarch Bartholomew as valuable defenders of support to refugees, and Greek Prime Minister Alexis Tsipras will go with (them) to the island of Lesbos," a government source in Athens said.
The holiday island of Lesbos has served as a major gateway for refugees and other migrants hoping to start new lives in Europe, with hundreds of thousands of people sailing there in flimsy boats from the nearby Turkish coast over the past year.
The government source declined to give a precise date for the visit by Francis and Bartholomew, but indicated it could take place on April 14 or 15.
The Greek Orthodox Church earlier said it had approved plans for a papal visit to Lesbos island after Francis expressed a desire to "shed light on the major humanitarian problem" of the migrant influx.
The process of returning migrants, mainly Syrians, to Turkey has been slowed "by an increase in asylum requests" in the last few days by migrants on Chios and Lesbos, the Greek Aegean islands in the front line of the migratory wave, said Greek official Yiorgos Kyritsis.
Kyritsis, the spokesman for the Greek government panel coordinating the migration crisis, said no operations were planned for today.
A Turkish official said the next transfer of migrants "has been postponed to Friday" at Greece's request
All "irregular migrants" arriving in Greece since March 20 face being sent back, although the EU deal calls for each case to be examined individually.
