South Sudan rebel chief Machar refuses to sign peace deal: Mediator

South Sudan rebel chief Riek Machar on Tuesday refused to sign a final peace deal with the government that aims to end a brutal civil war, a Sudanese mediator said.

"The main South Sudanese opposition groups, including the SPLM-IO (Machar faction), refused to sign the final document demanding that their reservations be guaranteed in it," Sudanese Foreign Minister Al-Dierdiry Ahmed told reporters.

The warring South Sudanese parties have held weeks of talks in Khartoum in search of a comprehensive peace deal to end the conflict in the world's youngest country that has killed tens of thousands of people and displaced millions since it erupted in December 2013.