African Union officials in Addis Ababa, trying to mediate an end to the devastating 15-month civil war in the Darfur region of western Sudan, are facing a second day of deadlock, after rebels set conditions that the government reportedly found unacceptable.

African Union mediators had hoped that Friday would mark the first day of serious face-to-face negotiations between the government in Khartoum and Darfur rebels. Instead, they spent the day in separate meetings with rebel leaders and Sudanese government officials, in an effort to keep Darfur's peace process from collapsing.

The stumbling block came early Friday, when the leaders of the Justice and Equality Movement and Sudan Liberation Army gave the government one month to meet six conditions they have set for the start of the talks.

The rebels say that Khartoum must, among other things, disarm pro-government Janjaweed militias in Darfur, and give access for an international inquiry into charges of genocide. At the start of the meeting in Addis Ababa Thursday, the rebels also called for the immediate withdrawal of government troops from Darfur, and also demanded that Khartoum renew its commitment to an April eighth cease-fire, which both sides are accused of violating. A Sudanese government spokesman has reportedly rejected some of the demands, calling them impractical.

Speaking from the African Union headquarters in Addis Ababa, AU spokesman Desmond Orjiako tells VOA that the deadlock is serious, but he says AU mediators are determined to bring the warring parties to the negotiating table.

"Yes, there are conditions, but these conditions have always been there,? he said. ?We're saying these conditions are not a substitute for dialogue and not a substitute to peace through dialogue. We believe the only way forward is dialogue, and that's what our position is."

Darfur rebel groups, the United Nations and human rights organizations accuse the Arab Muslim government in Khartoum of aiding mostly-Arab Janjaweed militias bomb, burn and loot African villages in a campaign of ethnic cleansing. The Sudanese government denies the charge.

The United Nations says the fighting in Darfur has displaced more than one million people, triggering the world's worst humanitarian disaster.

Efforts to end the conflict have gained increased urgency in recent weeks, with the start of the rainy season already affecting deliveries of humanitarian goods to hundreds of thousands of refugees in parts of Darfur and neighboring Chad.