Rwanda, which diplomats say backs M23 fighters who seized Goma in Democratic Republic of Congo this week, called on Wednesday for a ceasefire across eastern Congo and for Congo to negotiate with the rebels while denying Rwandan troops were involved.

Rwanda-backed rebels have captured large parts of the eastern Democratic Republic of the Congo’s largest city, including its airport, the United Nations said. The move in Goma comes as Rwanda’s President joined calls for a ceasefire in the decades-long conflict.