- Salva Kiir and Riek Machar were given another 100 days to form a power-sharing government.
- The delay was occasioned by the two leaders' failure to resolve their differences.
- It is the second time the deadline has been pushed back since the rivals signed a truce last September that brought a pause to fighting.
South Sudan President Salva Kiir and rebel chief Riek Machar on Thursday were given another 100 days to form a power-sharing government after failing to resolve differences, a fresh delay that prompted a sharp US warning that the fledgling nation needed new leaders.
The two rivals, whose fallout in 2013 sparked a conflict that has left hundreds of thousands dead, were granted the extension after a rare face-to-face meeting held with regional heavyweights in Uganda.
It is the second time the deadline has been pushed back since the rivals signed a truce last September that brought a pause to fighting.
Both sides had agreed to join forces in a coalition government by November 12. But with the date looming and key issues far from resolved, regional leaders brokered high-level mediations in Entebbe to chart a way forward.
"It was really impossible to have them reach agreement in five days. We've given them three months and we will continue our engagement," Ugandan Foreign Minister Sam Kutesa saud following the closed-door discussions at State House in Entebbe.
The meeting "agreed to extend the pre-transitional period... and to review progress after fifty days from that date", Kutesa said afterwards, reading from an official communique.
The United States, a major backer of the impoverished nation, voiced exasperation with the delay and said it would "review our relationship" with South Sudan's government.
"This inability to meet their own deadline calls into question their suitability to continue to lead the nation's peace process," Tibor Nagy, the top US diplomat of Africa, said of Kiir and Machar.
"The US is considering all possible options to put pressure on those individuals who would impede peace and promote conflict," he wrote on Twitter.
The United States has previously threatened targeted sanctions without a prompt government formation, although an official earlier ruled out ending Washington's roughly $1 billion in humanitarian assistance.
Nagy nonetheless voiced appreciation to the African mediators who included Ugandan President Yoweri Museveni; General Abdel Fattah al-Burhan, who heads neighbouring Sudan's sovereign council; and Kalonzo Musyoka, a special envoy from Kenya.