ABUJA, Nigeria, June 11, 2005 (AP) -- Sudan's government and Darfur rebels launched their latest peace effort with delegates meeting in Nigeria for talks aimed at calming a two-year conflict that has killed tens of thousands of civilians and sent hundreds of thousands fleeing.
Khalil Ibrahim, leader of the rebel Justice and Equality Movement, said Friday that the current peace parley in the Nigerian capital, Abuja, could be the last. It's the fifth round of as-yet unsuccessful talks.

"If you do not have peace now, then ... you will see the fabric of Sudan crumble," he told assembled negotiators. "I can tell you: This will be the last chance."

In New York, the office of U.N. Secretary-General Kofi Annan said that he "urges all parties to make full use ... Salim, so that an early political settlement to the conflict may be concluded. The Secretary-General emphasizes that lasting security for the people of Darfur can only be based on a negotiated resolution of the conflict."

Previous peace accords have so far failed to end conflict in Sudan's western Darfur region, which has led to an estimated 180,000 deaths. Around two million others have fled into the bush or relief camps in Darfur or neighboring Chad.

The conflict began when mainly ethnic African rebels launched a February 2003 uprising aimed at gaining autonomy from the Khartoum government. Sudan's Arab-dominated government and pro-government Arab tribal fighters are accused of launching coordinated attacks on ethnic African farmers in retaliation.

Sudan denies targeting civilians or allying with the so-called Janjaweed militia. Some have accused the government and militias of committing the 21st century's first genocide.

Sudanese officials have said the government is determined to resolve the Darfur crisis this time around. But they also have expressed concern an announcement this week that the International Criminal Court had begun investigating alleged war crimes in Darfur could be seen as anti-government and prompt the rebels to harden their positions going into the peace talks.

Sudan on Wednesday reiterated it would not hand any of its subjects over for trial outside the country.

However, both rebel groups -- the Sudan Liberation Army and the smaller Justice and Equality Movement -- said Friday that they welcomed the International Criminal Court's investigations.

"Our movement says today that it will cooperate fully with the International Criminal Court. We will assist it as much as we can," said the Justice and Equality Movement's Ibrahim.

The 53-nation African Union brokering the peace parley will also try to end fighting among rebels who are united in their opposition to the government but divided over their vision of the region's future.

NATO defense ministers finalized plans Thursday for the alliance's first African mission, agreeing to fly 5,000 African peacekeepers to Darfur.

While the allies will fly African troops into Darfur -- hopefully before the rains come in July -- they stressed the AU remained in charge of the peacekeeping operation. The AU now has some 2,700 peacekeepers in Darfur, site of one of the world's worst humanitarian catastrophes.

Annan's office said he "welcomes the news that NATO and the European Union will be airlifting African Union peacekeepers into Sudan's Darfur region -- something he has strongly advocated and sought to facilitate over the last six months or more."

Rebels and the government promised to abide by cease-fire agreements at two earlier rounds of peace talks in November and December last year, but rights groups say the government has since launched fresh bombing raids on Darfur.