Leaders of the Eastern Front, a coalition of Beja and Rashaidah Arab rebel groups, say they have little confidence Khartoum is truly interested in resolving problems in the eastern states of Red Sea and Kassala.
"The government wants just to win time," said Salah Barqueen, a leader of the Beja Congress, which along with the Free Lions makes up the front. "I do not believe that there will be peace talks."
Free Lions president Mubruk Moubarak Selim said the groups would not be dissauded from their goal of changing the Arab-dominated government.
"The objective is to change the government," he told AFP. "The government does not want peace with us. There will be more fighting between the government and the Eastern Front."
The pair spoke late Sunday as leaders from the two groups began a three-day conference here in rebel-held territory to thrash out a common stance ahead of promised talks with Khartoum.
Like their counterparts in the Darfur region of western Sudan, the ethnic minority rebels in Red Sea and Kassala states complain of marginalisation by Khartoum.
Sudan's biggest rebel group, the southern Sudan People's Liberation Army, once championed their cause but signed a landmark peace deal with the government in January that applied only to the south and disputed adjacent districts.
Both the Beja Congress and the Free Lions group, drawn from the descendants of 19th century immigrants from the Arabian peninsula, pulled out of the main opposition allinace last year, complaining that the mainstream northern political parties were ignoring their interests in talks with Khartoum.
The government pledged in mid-February to hold talks with the rebels after Beja demonstrations in the city of Port Sudan in January sparked a security force action in which at least 14 people -- and possibly as many as 23 -- were killed.