The State Department says it hopes the U.S. military airlift of more African Union (AU) peacekeepers into Sudan's Darfur region will help end continuing violence there. A U.S. transport plane brought 47 Nigerian troops into the area in an initial flight Thursday.

The U.S. airlift was delayed several days by bureaucratic and political snarls.

But the first flight of peacekeepers, from the Nigerian capital Abuja to the Darfur regional town of El Fasher, finally went ahead Thursday.

It has given rise to optimism here that the expanding African Union presence will help end continuing attacks in Darfur, attributed to both government-backed Janjaweed militiamen and local rebels.

The African Union earlier this month approved an expansion of its military presence in Darfur from 300 troops to more than three thousand, mainly a protection force for AU truce monitors already in the western Sudanese region.

Officials say the U.S. airlift will last about two weeks and carry both Nigerian and Rwandan troops along with support personnel and equipment. The transport operation will later be continued by Australian aircraft and crews.

The United States has provided more than $40 million for ground facilities and other services for the AU troops being furnished by private U.S. contractors. Additional support funds have been committed by the European Union, Australia, Canada and several individual EU member states.

At a news briefing, State Department spokesman Richard Boucher said security conditions have improved somewhat in recent weeks for displaced people in Darfur. But he said AU monitors are reporting continued attacks and that the Sudanese government has played what he termed "a particularly egregious role" by supporting the Janjaweed.

He said the Nigerian and Rwandan troops, though technically there to protect the truce observers, can intercede to prevent attacks and should provide a greater degree of stability in the region.

"Their primary mandate is to monitor the situation, observe the situation, and make sure that those who do observe are protected," he said. "But I think if you look at the mandate, you also see that they're empowered to intervene when there's imminent danger, that they are going to be deploying through a wide area of Darfur. The presence of observers, the presence of troops under the existing mandate, we think, can be a major stabilizing force, can help inhibit those who might perpetrate violence, and stop them."

Mr. Boucher said it remains vital that the Darfur parties abide by the cease-fire agreement they reached earlier this year in Chad, and work for a broader peace accord in talks, which resumed Monday in Abuja.

The Darfur conflict erupted early last year when rebels seeking autonomy for the largely- black African region took up arms against the Khartoum government.

An estimated 1.5 million African villagers have been displaced by scorched-earth warfare by the Janjaweed that the United States and human rights groups say constitutes genocide. The United Nations said earlier this month that the death toll in Darfur refugee camps has reached 70,000.