A top State Department official and Britain's International Development Minister are at the Darfur peace talks, trying to broker an agreement between Sudanese rebel factions and the government.
Deputy Secretary of State Robert Zoellick and Britain's Hilary Benn are meeting with Sudanese officials and rebel groups in Abuja, Nigeria.
Rebels want more power-sharing, wealth-sharing and security assurances in the African Union - brokered draft agreement. The Sudanese government has agreed to sign the current draft agreement.
The original deadline for reaching a deal has already been extended 48 hours until midnight Tuesday, but A.U. officials have indicated another extension is possible if the talks are making progress.
U.S. officials say only a few issues remain unresolved.
Three years of violence involving rebels, government forces, and government-backed militias in Darfur has killed an estimated 180-thousand people, and forced more than two million to flee their homes.
While in Abuja, Deputy Secretary of State Zoellick plans to meet with commanders of the African Union mission in Sudan to discuss the security situation in Darfur. The State Department says he also hopes to meet with Nigerian President Olusegun Obasanjo.
Some information for this report was provided by AFP, AP and Reuters.