Abuja, Nigeria ? The U.S. declaration that government-backed militiamen have committed genocide in Darfur is a “big mistake” that could hinder peace talks and undermine the role of African mediators in the conflict, Sudan’s top officials said Friday.

Secretary of State Colin Powell said Thursday the killing, raping and displacement of black Africans by the Arab fighters known as the Janjaweed amounted to genocide in the western Darfur region of Sudan. The United States and aid groups accuse President Omar el-Bashir’s government of backing the Janjaweed in the attacks on African villagers.

El-Bashir defended his government’s efforts to address the Darfur crisis, saying Friday the Darfur region “is moving toward constant improvement.” He called the situation in Darfur “reassuring” and said life has been normalized in most of the areas affected by war.

Sudan’s deputy foreign minister, Najeeb Al-Khair Abdel-Wahab, criticized Powell’s comments.

“We don’t think this kind of attitude can help the situation. …We expect the international community to assist the process that is taking place in Abuja, and not put oil on the fire,” he said.

Sudan government and rebel envoys have been attending Darfur peace talks in the Nigerian capital, Abuja, since Aug. 23 in an African Union-brokered effort to calm 19 months of violence that have left 30,000 dead and 1.2 million homeless. The United Nations calls it the world’s worst humanitarian crisis.

The violence in Darfur began when black African tribes rebelled in February 2003, accusing the national government in Khartoum of neglecting their interests. In response, Powell said, Arab militias coupled with Sudanese military forces “committed large-scale acts of violence, including murders, rape and physical assaults on non-Arab individuals.”

Abdel-Wahab, a top government negotiator in the peace talks, told reporters Powell’s statement “is sending a wrong signal” to rebel delegates at the talks. The insurgents “will bet on U.N. sanctions, they will want to wait for action to be taken by the U.N. Security Council — and for that reason they will not be forthcoming in negotiations,” he said.