Opposition Leader Dr Riek Machar jetted back to Juba on Monday afternoon for peace talks with President Salva Kiir.
President Kiir and Dr Machar, who is questioning the creation of three administrative areas, are expected to focus on the number of states and security arrangements.
The president reverted the country to 10 states last weekend, a day after he said he would “drop a single state”.
The international community had been pushing the two leaders to amicably resolve the issue of the number and boundaries of states, which has been a major factor impeding the establishment of a coalition government.
They are likely to set up a coalition government as scheduled on 22 February.