Machar had fled to Democratic Republic of Congo before he went to South Africa and lastly returned to Sudan which played a great role in enhancing communication between the two leaders.
The Vatican said that the retreat, which ends today, 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". This has certainly held true for South Sudan as recent government insurgency campaigns in Yei and Wau have included killings, looting, and burning of civilian property.
Archbishop Welby preached and Pope Francis delivered a discourse at the conclusion of the retreat on Thursday afternoon, after which participants were to be given a Bible signed by the church leaders and a former Moderator of the Presbyterian Church of Scotland, the Revd John Chalmers, with the message "Seek that which unites".
"I will never tire of repeating that peace is possible!" Reportedly, under the terms of a peace agreement which was signed in September, 2018, the vice presidents were to take office together on May 12, while sharing power and ending all the armed conflict between cans and among communities.
But Kiir might still be willing to form a unity government with Machar if Kiir thought he could improve relations with foreign powers, consolidate his power and pick off the last remaining rebel group, led by former general Thomas Cirillo, said the International Crisis Group's Boswell.
The leaders should use the opportunity of the Vatican meeting to make a clear, public commitment to holding those responsible for these crimes to account, recognizing this is a key component of lasting peace. "In other words, He will ask us to render an account not only of our own lives, but the lives of others as well", the pope said. The pope kissed the feet of all of them. The Vatican described the event as both ecumenical and diplomatic.
"We have clearly heard the cry of the poor and the needy; it rises up to heaven, to the very heart of God our Father, who desires to grant them justice and peace", he said. This way, Francis said, they can "become fathers of the nation".
South Sudan, gained independence from Sudan in 2011 and in 2013, the country plunged into a bloody civil war, which left at least 400,000 people dead.
A prior trip to the war torn country with Welby was cancelled in 2017 due to security concerns.
Francis sat at his desk in a small room inside the Vatican facing the South Sudanese leaders, who were seated on a couch.