U.S. Secretary of State Marco Rubio called for a urgent cease-fire in the conflict in eastern Democratic Republic of Congo saying Washington was "deeply troubled" by a recent escalation in the fighting.

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.

Angolan President Joao Lourenco, who’s been mediating peace talks between Rwanda and Democratic Republic of Congo, called for the withdrawal of Rwandan-backed M23 rebels from the city of Goma and for Rwandan troops to leave Congolese territory.