The pope, the first from the United States, is scheduled to visit Algeria, Cameroon, Angola and Equatorial Guinea, traveling nearly 18,000 km (11,185 miles) across 11 cities and towns on 18 flights in one of the most complex papal itineraries in decades.

Cardinal Michael Czerny said the trip was intended “to help turn the world’s attention to Africa,” underscoring the Vatican’s focus on a region where Catholic populations are expanding rapidly.

Leo, 70, has made limited overseas visits since his election last May, including trips to Turkiye and Lebanon late last year, and Monaco in March. The current tour marks his most extensive diplomatic and pastoral journey to date.

The visit will include a stop in Algeria, an overwhelmingly Muslim country with fewer than 10,000 Catholics among a population of around 48 million, marking the first time a sitting pope has visited the country.

Leo is expected to address political leaders there and visit the Great Mosque of Algiers, only his second visit to a mosque as pope.Across the four countries, Leo is scheduled to deliver 25 speeches addressing a range of issues including resource exploitation, interfaith dialogue and political governance, according to Vatican spokesperson Matteo Bruni.

Cameroon and Equatorial Guinea have long-serving leaders who have faced allegations of human rights abuses, which they deny.The largest gathering of the tour is expected in Cameroon’s coastal city of Douala, where Vatican officials estimate around 600,000 people could attend a papal Mass on Friday.

The trip is the 24th papal visit to Africa since the late 1960s and reflects the continent’s growing significance within the global Catholic Church, with more than 20 percent of adherents now based there.