Democratic Republic of Congo President Felix Tshisekedi has vowed “a vigorous and coordinated response” against a rebel alliance that has besieged swaths of the nation’s mineral-rich east and forced hundreds of local troops and foreign mercenaries to surrender.

Congolese President Félix Tshisekedi has vowed to restore government authority in the east, where Rwanda-backed M23 rebels have seized much of the city of Goma and are reportedly advancing south to seize more territory.

Democratic Republic of Congo President Felix Tshisekedi, speaking publicly for the first time since Rwandan-backed rebels seized the eastern city of Goma, said his government was preparing a response and warned of “unpredictable consequences” for the region.