The Rapid Support Forces said it was paving the way to an end to the civil war. Critics called it an audacious gambit by a group that the United States has accused of genocide.

Sudan’s paramilitary Rapid Support Forces and allies have signed a charter that paved the way for the establishment of a parallel government, as Sudan’s army made advances recently against the rival groups.

The RSF has seized most of the western Darfur region and swathes of the Kordofan region in an almost-two-year war, but is being pushed back from central Sudan by the Sudanese army.