"Pope Francis was very delighted to receive us," he said. "Of course he is the father of the Church, our father, so we felt at home; the meeting was warm."
One of the most serious problems both Sudan and South Sudan face is the humanitarian crisis brought about by their years of war and internal conflict.
"Right now we have people suffering in South Sudan and war in South Sudan," Bishop Santo said. "Displaced people move to Sudan, and then displaced people move from Sudan to South Sudan, so we have crossroads of displaced people in both countries suffering from the political elite who don't take their people in heart."
The majority of issues the country faces are political problems "that have been created by the ruling elites in all Sudan," making life difficult for both Christians and Muslims alike, he said.
In the beginning, war "was created by this political elite, using fundamental ideologies in order to make life difficult," the bishop said, explaining that while the situation has somewhat improved since South Sudan's 2011 secession, "the political war is still in place."
The South Sudanese Civil War has been characterized as having both political and ethnic dimensions, and it is estimated that thousands of people have been killed and millions displaced from their homes since the violence began.
This war "is what the bishops are praying should come to the end sooner or later because the suffering is too much," Bishop Santo said.
He offered thanks to the international organizations assisting in the humanitarian crisis on the ground in conflict areas.
Many humanitarian workers "risk their lives, they leave their countries, they go down to help us," but at the same time are blocked by the government from getting the aid to those who need it, the bishop said, noting that at times they are even harassed "in carrying out this noble humanitarian task."
He made an appeal to the governments of both Sudan and South Sudan to drop political interests and help with the crisis "so that aid can reach those in need."
"This is very urgent and it is needed now, because if the people are cut off, (if) they lack medicines, they lack water, they lack food, many of them will die."
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With water points far and hard to get to as the hot season approaches, the need is becoming even more dire, the bishop said, adding that "if this conflict continues in the dry season it's going to affect millions and millions of people."
"So we continue to appeal that the international community. Most urgently we would like to see that these people are safe. Once they are safe and protected then they will need the basic necessities of life."
Bishop Santo drew specific attention to the need for education for displaced children, who are particularly vulnerable and "who are not part of this war, but it is brought to them. So this is very, very urgent and very urgently needed now more than before in both countries."
According to a recent report from Unicef South Sudan has the highest proportion of children unable to attend school, at 51 percent.
Many youth in Sudan and South Sudan have left and joined terrorist groups in neighboring countries such as Chad and the Central African Republic. Given the political situation and the war, it's very difficult for young people to find opportunities for education and a better life, the bishop said.
"Therefore when the extremists came to Sudan, especially, they offered chances and these young people embraced these chances and began to go into this violence."