By Philip Pullella
VATICAN CITY (Reuters) - Pope Francis and two other religious leaders sent out an extraordinary Christmas appeal on Wednesday to the leaders of South Sudan to keep their promise to form at least a transitional unity government early next year.
The brief message was signed by Francis, worldwide Anglican leader Archbishop Justin Welby, and Rev. John Chalmers, former moderator of the Church of Scotland.
The country, the world's youngest, is mostly Christian, and a stable peace would allow the pope to visit, something which he has said he hopes to do next year.
In the message, the three religious leaders said they were praying for "a renewed commitment to the path of reconciliation and fraternity".
Last month, President Salva Kiir and former rebel leader Riek Machar delayed forming a unity government for 100 days beyond the Nov. 12 deadline, which itself was an extension of an original deadline last May.
They agreed to form a transitional unity government if they fail to resolve all their differences before the end of February.
The religious leaders said they wanted to show the political leaders "our spiritual closeness as you strive for a swift implementation of the Peace Agreements".
The message is extraordinary because on Christmas day, the pope usually combines peace appeals in his "Urbi et Orbi" (to the city and the world) address.
Last April, weeks before the original deadline, the religious leaders brought Kiir, Machar and other politicians to the Vatican for a retreat.
In a dramatic gesture on the last day of the retreat, Francis knelt at the feet of the previously warring leaders as he urged them not to return to a civil war that ended with a shaky peace deal in 2018.
Sudan, which is predominantly Muslim, and the mainly Christian south fought for decades before South Sudan gained independence in 2011.
(Reporting by Philip Pullella; Editing by Hugh Lawson)