The return of rebel leader Riek Machar to Juba must pave the way for a genuine transition to end more than two years of brutal civil war in South Sudan, the UN peacekeeping chief said Tuesday.
"The return of the designated first vice president should open a new chapter for the country. It should allow the real transition to begin," Herve Ladsous told the Security Council.
The 15-member council met to discuss the two-year war in South Sudan just as Machar was sworn in as vice-president in a new unity government with President Salva Kiir.
Machar's return on a UN plane marked a turning point in the international effort to force the rebel and government sides to implement a peace accord that was signed in August but has yet to take hold.
Under the peace deal, Machar will serve alongside Kiir in the new 30-month transitional government leading to elections.
"It's vital that the parties take this opportunity to show their genuine determination to move forward with the peace process," said Ladsous.
South Sudan Deputy UN Ambassador Joseph Moum Malok said the new transitional government should be formed "in a day or two after consultations with the different parties in the country."
- Turning up the heat -
US Ambassador Samantha Power said that while Machar's return marked an important step, international powers remained "clear-eyed" about the challenges ahead.
The new government will have to tackle security sector reform to end fighting, corruption and in particular, pick up the pace on the creation of a special African Union court to try war crimes suspects, said Power.
The Security Council is determined to keep the pressure on Machar and Kiir to implement the peace accord, she added.
"When things are going to happen in South Sudan, it tends not to happen because of gravity. It happens because the international community unites and turns up the heat," she said.
South Sudan's war began in December 2013, when Kiir accused Machar of plotting a coup.
The conflict has torn open ethnic divisions and been characterized by horrific rights abuses, including gang rapes, the wholesale burning of villages and cannibalism.
Tens of thousands of people have been killed and more than two million have been driven from their homes in the war.
Machar had been expected in the capital last Monday, but last-minute disputes over the security arrangements including the weapons that rebel troops would be allowed to carry led to delays.
The Security Council last week had expressed serious concern over the delays and urged all sides to quickly form the transitional government and move to implement the peace agreement.
