AlQa'dah 02, 1436, August 17, 2015, SPA -- South Sudanese President Salva Kiir on Monday refused to sign a peace deal that was accepted by rebel leader Riek Machar, as the two came under strong international pressure to end their 20-month military conflict. The deal, the contents of which were not immediately known, was signed by Machar and a representative of East Africa's Intergovernmental Authority on Development (IGAD), which has overseen several rounds of talks in Addis Ababa. South Sudanese ruling party's secretary-general Pagan Amum also signed the agreement, but diplomats said he did not represent the government. Kiir only witnessed the signing of the agreement. "They have certain reservations about which they have decided to go into their country and consult," said the IGAD's Seyyoum Mesfin, without explaining what the reservations were. Mesfin said that Kiir would return to Addis Ababa within 15 days to "finalize the peace agreement."