Renewing their pledge to visit South Sudan, Pope Francis and Anglican Archbishop Justin Welby of Canterbury urged the political leaders of the country to start trusting one another and give their people the peace they need and deserve.

"We have been glad to see the small progress you have made, but know it is not enough for your people to feel the full effect of peace," said the letter, which also was signed by a Presbyterian minister, the Rev. Martin Fair, moderator of the General Assembly of the Church of Scotland.

The religious leaders noted that in April 2019, when the pope and Archbishop Welby hosted a retreat for South Sudan's government and opposition leaders, commitments were made: "yours to bring your country to a smooth implementation of the peace agreement, and ours to visit South Sudan in due course, as things return to normalcy."

"In this Christmas season," they said, "we remember that our Lord Jesus Christ came into the world among the least -- in a dusty stable with animals. Later, he called those who wish to be great in his kingdom to be the servant of all."

South Sudan's war broke out in 2013, two years after the country achieved independence, and has left nearly 400,000 people dead and has displaced nearly 4 million people.

Government officials and members of the South Sudan Opposition Movements Alliance signed a new peace agreement in Rome in January, giving rise to hope that an end to the fighting might be near.

In early December, in sessions hosted by the Sant'Egidio Community in Rome, both sides continued their negotiations, coming to agreements on the federal nature of country's government and the division of powers, the need to respect ethnic, cultural and linguistic differences and the creation of a National Constitutional Conference and a National Constitution Review Commission.

However, they reported ongoing disagreements over whether the current conflict is ethnic in nature and over whether to hold a general referendum to approve the new constitution, which is currently being drafted.

Pope Francis, Archbishop Welby and Rev. Fair told the leaders, "When we visit, we long to bear witness to a changed nation, governed by leaders who, in the words of the Holy Father last year, 'hold hands, united ... as simple citizens' to 'become Fathers (and Mothers) of the Nation.'"

"We pray, this Christmas, that you will know greater trust among yourselves and a greater generosity of service to your people," the three Christian leaders wrote. "We pray you know the peace that surpasses understanding in your own hearts and in the heart of your great nation."