The latest dispute over the presence of Eritrea and Chad prevented a scheduled meeting on Saturday, one day after a new round of talks was officially launched in Nigeria's capital of Abuja after a six-month gap.
Sudanese Agriculture Minister Majzoub al-Khalifa, who heads the government delegation, told the press here that the government opposes Eritrea, which "is always backing the anti-government forces," as "observer or mediator" at the talks.
Meanwhile, the rebel groups rejected the presence of Sudan's western neighbor Chad, accusing the country as "a destroyer of peace" siding with the Sudanese government.
The Darfur conflict, which flared up in early 2003, has claimed the lives of tens of thousands of people and driven more than 1.8 million others from their homes.
The African Union has brokered a shaky cease-fire and struggled to find a political solution through three previous rounds of Abuja talks, which however failed to get substantial agreements.
And this time, although both the government and the rebel groups said they were optimistic about the talks, they have so far failed to agree on the agenda of the negotiations.