The formation of the new government, which became possible after a January peace deal, was delayed after a helicopter crash on July 30 killed John Garang, the former leader of the Sudan People’s Liberation Movement (SPLM).
Salva Kiir, who took over as leader of the SPLM and first vice president of Sudan, will meet President Omar Hassan al-Bashir late on Saturday for talks that may last until Monday, the official who declined to be named told Reuters.
"This is a really important meeting ... The two sides have decided most of the details. There are a few major things left to discuss and then the new government will be formed," the official said. "According to our schedule we should have a new government by Sept. 7."
SPLM officials said earlier they expected the announcement of a new government by the end of August or early September.
According to the peace deal that ended a more than 20-year north-south civil war, the ruling National Congress Party will form 52 percent of the government, the SPLM will form 28 percent and other political groups will form the remainder.
The National Congress Party held a meeting on Saturday to finalise the officials it would hand positions in its control.
The SPLM official said the group had also decided which officials it would place in the positions under its control. But, he added among the issues still to be decided included control of the budding oil producer’s energy ministry.
Political commentator Faisal Mohamed Salih said after the formation of the new government, the SPLM will concentrate on building bridges with other southern groups, some of whom allied with the government against the SPLM during the civil war.
"There will more emphasis on south-south dialogue after the new government is decided," he said, adding that Kiir had created a good atmosphere for compromise among southern leaders.
Analysts have said Kiir has a more collegial style of leadership than Garang, who maintained a tight grip on power.
SPLM officials say progress has been made on incorporating a number of southern militias into the group’s forces.