The final text was scheduled to be signed on Tuesday, but Machar and the leader of another still anonymous armed group demanded assurances from the South Sudanese president, Salva Kiir, that he would respect the letter and spirit of the text.
In addition, they have doubts about the functioning of the government of shared authority, the number of states into which the country will be divided and the drafting of a new Constitution, according to specifications.
The agreement had been already signed by the South Sudanese government representation, but was awaiting the signature of Machar, who must be appointed first Vice President to share power with the president.
Both men, who commanded the armed movement which forced the government of Sudan to accept the secession of southern Sudan, have been at odds since 2013 when Kiir accused Machar of conspiring to assassinate him and usurp power.
The struggle unleashed a civil war which has cost the world’s youngest country hundreds of thousands of dead and wounded, paralysing its main economic activity, extracting oil and displacing the refugee status of millions of people, many of whom died on the roads.