Members of Sudan Liberation Army walk out of the meeting in Abuja, Nigeria, on Friday. ((George Osodi /Associated Press))

The government of Sudan and the largest Darfur rebel group, the Sudan Liberation Army,signed a peace treaty Friday, as two smaller rebel groups continue to reject the deal.

The agreement, intended to bring an end to fighting that has led to the deaths of 180,000 people through killings, illness and starvation,and displaced two million, was presented to all three factions on Thursday.

There are reports that some members of the small rebel factions, a breakaway faction of the SLA and the Justice and Equality Movement (JEM), were unhappy their leaders rejected the deal. Butthe large group has moved ahead with the signing.

"Today the largest group … has agreed to sign and the government of Sudan (has) agreed to sign as well," U.S. deputy state secretary Robert Zoellick told Associated Press.

UN Secretary-General Kofi Annan has urged the international community to press for an agreement, and said civilians in Darfur must be protected, even if by force.

Representatives from the African Union, the United States, the European Union and Britain have been in intense negotiations in Nigeria all week with the Sudanese government and the rebel groups after a Sunday deadline passed without agreement on a peace deal.

The government agreed to the deal last weekend, but the rebels refused, demanding a greater share of wealth and power.

The most recent revisions to the peace plan include concessions on integrating rebel fighters into the Sudan military, compensation for war victims and power-sharing.

The militant groups, mostly non-Arab tribes, began fighting in 2003 against the Arab-dominated government.

The government has been accused of backing Arab militias known as the Janjaweed, which have been fighting the militants and are accused of mass rapes and genocide.