The Vatican has invited South Sudan's president and opposition leader for a two-day spiritual retreat meant to foster peace and build confidence in a fragile peace deal after the country's five-year civil war.

South Sudan's opposition leader Riek Machar was traveling Wednesday to the Vatican, while President Salva Kiir was already in Rome and meeting with Italy's premier.

The Vatican said that the retreat, which ends Thursday, was an opportunity for "reflection and prayer" as well as an "encounter and reconciliation" to those who have "the mission and responsibility to work for a future of peace and prosperity for the South Sudanese people." The Vatican described the event as both ecumenical and diplomatic.

Machar, who has been under house arrest, had to receive permission to travel.