UN chief shocked by letter from Sudan's Burhan

U.N. Secretary-General Antonio Guterres was shocked by a letter on Friday from Sudan's military leader General Abdel Fattah al-Burhan, said a U.N. spokesperson, which - sources told Reuters - asked for the U.N. special envoy in Sudan to be replaced.

"The Secretary-General is proud of the work done by Volker Perthes and reaffirms his full confidence in his Special Representative," U.N. spokesperson Stephane Dujarric said.