Peace talks between Sudan's government and rebels have adjourned without a deal after a week of negotiations in Ethiopia, African Union mediators said Tuesday.

Rebel factions from the war-torn western Darfur region as well as the Sudan People's Liberation Movement-North (SPLM-N), fighting the government in the southern Blue Nile and South Kordofan states since 2011, met with government delegates from Khartoum.

Mediators had hoped both sides would declare a ceasefire, including to allow aid in for civilians in rebel areas.

African Union teams, led by former South African president Thabo Mbeki, adjourned talks late on Monday, an AU official said.

No date was given for when the next round of talks may start again.

Darfur has been mired in conflict since 2003, when insurgents rebelled against President Omar al-Bashir's Arab-dominated regime, complaining of marginalisation.

Rebels in Blue Nile and the Nuba Mountains of South Kordofan, areas bordering South Sudan, are fighting for similar reasons.

Some 300,000 people have been killed in Darfur and nearly 2.5 million displaced, the UN says, while the International Criminal Court has indicted Bashir for alleged war crimes committed during the conflict.