Sudan peace talks stalled before they began in Juba on Wednesday as a key rebel grouping said it refused to negotiate with Khartoum, claiming government forces were still bombarding its territory.

Juba is hosting talks between the government of new prime minister Abdalla Hamdok and representatives from two umbrella groups of rebels that fought forces of now ousted president Omar al-Bashir in Darfur, Blue Nile and South Kordofan states.

The talks were launched on Monday in the presence of heads of state from Ethiopia, Egypt, Rwanda, Uganda and South Sudan.

The first face-to-face meeting between the adversaries was to take place in the South Sudan capital on Wednesday.

But Amar Amoua, secretary general of the Sudan People's Liberation Movement North (SPLM-N), told journalists his group would not continue unless the government withdrew from the area of the fighting, in the Nuba Mountains.

"Our coming back to negotiate... is bound by government decisions to clear all these things," Amoua, who is representing three different rebel movements, told journalists. He said that for the past 10 days government forces had continued to attack their territory despite an unofficial ceasefire.

A chief was killed in the Nuba Mountains and several businessmen had gone missing, he charged. "The government should withdraw its forces and stop... occupying new areas, we will not allow that," he said.

Copyright Agence France-Presse, 2019