The United States, France and Britain pressured Rwanda on Sunday over its support for rebels rapidly closing in on eastern Congo's largest city, as government forces struggled to halt an offensive that has forced thousands of civilians to flee.

The Democratic Republic of the Congo (DRC) on Saturday announced the recall of its embassy staff in Rwanda amid advances by the March 23 Movement (M23) rebellion, which fueled diplomatic tensions between Kinshasa and Kigali.

The M23 armed group has seized further territory in the east of the Democratic Republic of Congo and on Thursday was continuing to tighten its grip on provincial capital Goma, which is almost surrounded by fighting.