Pope Francis, the Archbishop of Canterbury and the Church of Scotland Moderator will meet people displaced by war in South Sudan and hear their stories on Saturday in one of the high points of their visit to the struggling African nation.
The three Christian leaders, on an unprecedented "pilgrimage of peace", will later take part in an open-air ecumenical prayer vigil at a mausoleum for South Sudan's liberation hero John Garang, with 50,000 people expected to attend.
The joint visit by leaders of the Roman Catholic, Anglican and Reformed traditions is the first of its kind in Christian history.
South Sudan, the world's newest country, broke away from Sudan in 2011 but plunged into civil war in 2013 with ethnic groups turning on each other. Despite a 2018 peace deal between the two main antagonists, bouts of inter-ethnic fighting have continued to kill and displace large numbers of civilians.
There are 2.2 million internally displaced people in South Sudan, out of a total population of about 11.6 million, and another 2.3 million have fled the country as refugees, according to the United Nations.
Extreme poverty and hunger are rife, with two thirds of the population needing humanitarian assistance as a result of conflict as well as three years of catastrophic floods.
South Sudan is predominantly Christian and tens of thousands of people lined the streets of the capital Juba to welcome the pope with singing, drumming and ululations on Friday when he arrived from a visit to Democratic Republic of Congo.
In a strongly worded speech to South Sudan's leaders including its previously warring President Salva Kiir and Vice-President Riek Machar, Francis implored them to renounce violence, ethnic hatred and corruption.
"No more of this!" he said. "No more bloodshed, no more conflicts, no more violence and mutual recriminations about who is responsible for it."
At the same event, Archbishop of Canterbury Justin Welby said he was grieved that violence had continued after the 2018 peace deal and a 2019 gathering at the Vatican during which the pope knelt to kiss the feet of the warring leaders, begging them to bring peace to South Sudan.
"When I remember the commitments that were made by you in 2019 I am grieved. I am sad that we still hear of such tragedy. We hoped and prayed for more. We expected more. You promised more," Welby told the assembled leaders.
"We cannot pick and choose parts of a peace agreement. Every part must by done by every person and that costs much," he said, adding: "It is within your reach."
In his own speech, Kiir said his government was firmly committed to consolidating peace in South Sudan.