Senior US and British officials have increased pressure on the warring parties from Sudan's Darfur region to strike a peace deal before a midnight deadline to end the three-year conflict.
The government of Sudan has accepted an 85-page draft settlement but two main Darfur rebel groups refuse to sign, saying they are unhappy with the deal on security, power-sharing and wealth-sharing.
US Deputy Secretary of State Robert Zoellick and Britain's International Development Secretary Hilary Benn flew to the Nigerian capital, Abuja, and observers said their arrival could help jolt the rebels into signing.
The conflict has left up to 300,000 people dead from violence and famine and 2.4 million homeless.
