The Security Council is calling for a strategic review of the U.N. peacekeeping mission in Congo with a view to progressively handing over its responsibilities to the country's newly elected government led by President Felix Tshisekedi.

A resolution adopted unanimously by the council on Friday asks Secretary-General Antonio Guterres to provide members with an independent review by Oct. 20 "assessing the continued challenges to peace and security ... and articulating a phased, progressive and comprehensive exit strategy."

The resolution extends the mandate of the more than 18,000-strong peacekeeping mission — the U.N.'s biggest and most expensive with a budget over $1.1 billion — until Dec. 20 with a priority mandate of protecting civilians and supporting "the stabilization and strengthening of state institutions."