Two Darfur rebel groups are being pressured to sign a peace agreement before the expiration of an African Union-imposed deadline Wednesday.

AU officials say members of both rebel groups have approached them and expressed a willingness to sign.

Leader of Darfur's Justice and Equality Movement Khalil Ibrahim

But leaders of one of the groups, the Justice and Equality Movement, said again today that the group will not sign the accord without significant changes.

The JEM leaders did not specify the changes they want, although the Associated Press quotes group leader Khalil Ibrahim as saying the peace deal does not provide "a fair share of resources and power."

Sudan's government and the main Darfur rebel group - the Sudan Liberation Movement concluded the deal in Nigeria earlier this month.

The document is aimed at ending more than three years of conflict in Darfur that has killed at least 180,000 people.

The deal stipulates a more equitable distribution of power and wealth, the disarming of pro-government Janjaweed militias, and a referendum on Darfur's future.

Besides the JEM, a faction of the main Darfur rebel group is refusing to sign. African Union officials say if the rebels do not sign the accord, the AU Peace and Security Council will discuss what measures could be taken against them.

Two million people have been displaced by the chaotic fighting in Darfur involving the rebel groups, the Arab-dominated Sudanese government and the Janjaweed militias.