Talks to secure a lasting ceasefire in Sudan's three war-ravaged regions began on Tuesday, a day after an opposition coalition signed on to a roadmap for ending hostilities and achieving political reconciliation.
There has been fighting between the Sudanese army and rebels in the southern regions of Kordofan and Blue Nile since 2011, when adjacent South Sudan declared independence.
Conflict in Darfur began in 2003 when mainly non-Arab tribes took up arms against the Arab-led government based in the capital Khartoum.
The roadmap, brokered by the African Union, marks the first time the country's major opposition groups have signed a deal with the government since regional fighting reignited in 2011.
The accord spells out a process for reaching a permanent ceasefire, endorses a national dialogue between the government and opposition rebel and political groups, and includes provisions for immediate humanitarian assistance.
Although violence has eased in recent years, an intermittent insurgency has continued. At least 130,000 people have fled fighting in the central Jebel Marra area of Darfur since mid-January alone.
Khartoum signed the AU plan in March, but opposition groups, many of which call for the overthrow of veteran President Omar al-Bashir, refused at the time to follow suit.
"We signed yesterday in Addis Ababa after the African intermediary agreed to include our demands in the agreement," Justice and Equality Movement (JEM) spokesman Jibril Bilal said.
The Darfur leader was referring to a clause ensuring preliminary meetings in the Ethiopian capital among all political groups before a national dialogue in Khartoum.
"The signing of the roadmap is a positive step, but the more complex stage will come with talks revolving around a ceasefire and a political solution," said Bilal.
Signatories to the roadmap included many of the country's most prominent opposition and rebel groups, from JEM and the Sudan People's Liberation Movement-North (SPLM-North) to the Umma Party, the largest opposition party.
"We welcome the opposition signing of the roadmap and today the government begins to engage in negotiations with armed rebels over a ceasefire...We are optimistic...It's important that a creasefire is reached to stop the war," government spokesman Ahmed Bilal said.
Holdouts to the roadmap remain, however, with the Sudan Liberation Movement, a major rebel force in Darfur, and the country's communist party refusing to sign.
"We are ready to reach necessary political solutions for the country, but this is tied to the will and desire of the other side, the government, for peaceful solutions," JEM's Bilal said.