Earlier this afternoon, President Obama called First Vice President of Sudan, Salva Kiir to discuss the status of peace negotiations and underscore the United States' commitment to a peaceful and on-time referendum on Southern Sudanese self-determination that is just 16 days away. The President underscored the importance of Vice President Kiir's leadership during this volatile time period in Sudan's history and urged Kiir to engage seriously with the National Congress Party in the coming days to resolve the outstanding issues related to Comprehensive Peace Agreement (CPA) implementation and take actions to prevent outbreaks of violence. The two agreed to continue the dialogue on the United States and the future of Southern Sudan.
Barack Obama, Readout of the President's Call with First Vice President of Sudan Salva Kiir Online by Gerhard Peters and John T. Woolley, The American Presidency Project https://www.presidency.ucsb.edu/node/290125