The authorities in power since longtime dictator Omar al-Bashir was ousted in a pro-democracy uprising have made ending the country's myriad internal conflicts a top priority.

Multiple rebel groups signed onto the October peace deal, although the SPLM-North under Abdelaziz al-Hilu signed a separate ceasefire.

The group represents the areas of South Kordofan and Blue Nile state which have significant Christian populations who have fought for decades to end the imposition of Islamic law by Khartoum.

It did not join the October accords, as it is demanding separation of state and religion.

In March, the government and the SPLM-North signed an agreement laying out their priorities.

This round of negotiations is to focus on political, economic, humanitarian and security issues.

The head of Sudan's civilian-military ruling council General Abdel Fattah al-Burhan and Prime Minister Abdalla Hamdok both attended the resumption of talks in the capital of South Sudan, Juba.

South Sudan's President Salva Kiir -- who is mediating the talks -- urged both sides to "embrace the spirit of dialogue and let their attention shift to peace instead of thinking of war."

"I believe that war will never save us. You have seen we (the South Sudanese) fought for 21 years up to 2005, with all of that we did not get what we wanted in full," said Kiir.

Hundreds of Sudanese women, men and youths, mostly from the Nuba mountains in South Kordofan -- an area which has witnessed deadly clashes in recent years -- sang songs of freedom as they gathered for the start of the talks.

"We affirm our commitment to a peaceful settlement and to the negotiations and mechanisms to resolve the root causes of the conflict in Sudan," said al-Hilu.

Meanwhile al-Burhan said his team "came to the negotiation this time around with an open heart and is determined to achieve peace for Sudan that complements what has started in the previous agreements."

United States special envoy for Sudan and South Sudan Donald Booth said the two sides should demonstrate "the political will to build on the momentum on the declaration of principles to reach a peace agreement in a near future."