"Much of the violence," they added, "is being perpetrated by government and opposition forces against civilians," especially those of ethnicities deemed to be in alliance with rebel factions. And those victims "are prevented from harvesting their crops," the bishops added.
Some members of the government have frustrated local peace deals brokered by the Church, the bishops said, and churches, priests, and nuns have been attacked.
The U.S. has sent "$2 billion since 2014 in humanitarian aid alone," Corkery said, but the United Nations humanitarian workers only operate in "certain pockets" of the country.
Amid this crisis and growing famine, Catholic priests, nuns, and missionaries have been laboring to bring food and supplies to remote areas and are "reaching these people who are truly destitute and starving."
It is not an easy task. Aside from the ongoing conflict where soldiers could seize food and supplies if they were aware they were being transported, the country's logistical infrastructure is so poor there are no paved roads outside the capital city of Juba, Corkery noted. During the country's rainy season, this problem is expanded.
"The real heroes that I see there," Corkery said, are the "missionaries toiling away on the front lines."
"These people are looking at the long-term solution in terms of the eternal scheme of things, people's souls."
Several aid workers with Samaritan's Purse were detained or kidnapped by opposition fighters near Mayendit March 13.
South Sudan announced earlier this month it plans to charge $10,000 per visa for foreign aid workers.
"The government and the army have largely contributed to the humanitarian situation. And now, they want to create profit from the crisis they have created," Elizabeth Deng, South Sudan researcher with Amnesty International, said in reaction to the announcement.
Despite the heroic efforts of missionaries, the Sudan Relief Fund, and other aid groups like Aid to the Church In Need and Samaritan's Purse, a long-term peace is the only lasting solution to the country's problems, Corkery insisted.
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Prayer is the most important thing Catholics in the U.S. can do to help the situation, he said, as peace can only come about through "prayer and grace working in the hearts and the minds of these warring tribes and factions."
However, citizens can also ask members of Congress to "push the U.S. government to put more pressure" on South Sudanese leaders. The U.S. has already begun listing "top leaders as war criminals" there, he said.
Pope Francis has spoken about the crisis in the country and has expressed his desire to visit there. No details of the trip have yet been released, Corkery said.
"The Pope and the Church," he said, "are the only people that have the ability to convene, bring the parties together" for a peaceful solution. Pope Francis will try to "refocus the international community on the gravity of this crisis that's there" and "convene the warring parties to try to bring them to the table to get some peace."