President Salva Kiir and key South Sudanese opposition leaders without exception have appended their signature on the agreements on governance on Sunday putting aside their concerns over the power-sharing and number of states.
"This agreement (2018) will not collapse and I am sure that it will not collapse because the people of South Sudan have now agreed that they must make peace among themselves", he said.
Presidents Yoweri Museveni (Uganda), Ismael Omar Guelleh (Djobouti), host Omar al-Bashir and Somalia Prime Minister Hassan Ali Khayre witnessed the signing of the peace pact.
"The agreement we have just signed today must map the end of conflict and war in our country", Kiir said after signing the deal. This is why when I came sign.
Thousands of people have died in the 2013 civil war after troops loyal to the rebel Machar clashed with government troops.
The opposition coalition of the South Sudan Opposition Alliance (SSOA) and other opposition factions who had earlier rejected the deal due to differences over the contents of the accord have all signed the pact.
It also stipulated that the transitional cabinet would be composed of 35 ministers from both the government and the opposition, including 20 ministers from the government, and nine from the Machar-led Sudan People's Liberation Movement-in-Opposition (SPLM-IO). The Parliament will have 550 members, 332 from Kiir's group and 128 from Machar's group.
"My government and I know the conflict in South Sudan has resulted in a financial and political burden", Kiir said.
A similar peace deal was signed in 2015 but fell apart a year later in a deadly battle that saw Machar flee into exile.
The day before, the President, after meeting with the Sudanese Foreign Minister, told the press that he is committed to the agreement to share power and promised that it will not collapse like the previous ones.
The UN estimates that about 4 million South Sudanese have been displaced internally and externally.