South Sudanese President Salva Kiir’s refusal to sign a deal to end an 18-month civil war was “mind-boggling”, the chief mediator has said.
Regional body Igad would say “enough is enough” if he failed to sign in 15 days, Seyoum Mesfin told the BBC.
Fighting between government and rebel forces has resumed following Mr Kiir’s failure to endorse the deal on Monday.
Nearly two million people have been left homeless since conflict broke out in the world’s newest state in 2013.
Rebel leader Riek Machar signed the accord in Ethiopia’s capital, Addis Ababa, on Monday – the deadline set by mediators.
He accused Mr Kiir of choosing war over peace.
International sanctions had been threatened by mediators if both sides failed to reach an agreement on Monday.
South Sudan’s elusive peace:
- At least seven ceasefires agreed and broken since conflict started in December 2013
- Nearly one in five South Sudanese displaced by the current conflict, from a total population of 12 million
- Former rebel leader Salva Kiir became president of South Sudan, the world’s newest state, when it gained independence in 2011
- South Sudan has been at war for 42 of past 60 years
Mr Kiir’s chief negotiator has said the deal is a sell-out, that cannot not be implemented as the rebels were split.
But Mr Seyoum told the BBC that all the government’s concerns had been addressed.
This included issues around the formation of a power-sharing government and the deployment of a neutral force to the capital, Juba, he said.
“This is a senseless war,” Mr Seyoum added.
He said the UN and African Union would be asked to “take over” if Mr Kiir failed to sign in 15 days.
“South Sudanese leaders have missed numerous opportunities to end the conflict but second chances don’t come always,” Mr Seyoum told the BBC.
Rebel general James Koang Chuol said his troops had seized the key town of Pageri, near the border with Uganda, after beating back government forces, AFP news agency reports.
Fighting also took place in the Manyo district in oil-producing Upper Nile state, where government troops repulsed a heavy attack by rebels, army spokesman Philip Aguer told AFP.
The claims of both sides could not be independently verified.
Conflict broke out in 2013 after Mr Kiir accused Mr Machar, his former deputy, of plotting a coup.