A retreat at the Vatican for the leaders of South Sudan enters its second day, a month before the end of the pre-transitional period of a shaky peace deal.

South Sudan President Salva Kiir is meeting with opposition leader Riek Machar.

Vatican Secretary of State Cardinal Pietro Parolin said the retreat is "dedicated to reflection and prayer" at the Vatican's Casa Santa Marta.

The meeting brings together the highest civil and ecclesiastical authorities of South Sudan, which gained independence from Sudan in 2011. In 2013, the country plunged into a bloody civil war, which left at least 400,000 people dead.

Pope Francis is scheduled to meet the participants on Thursday afternoon at the end of the retreat and make a statement.