A top United Nations official has expressed grave concern over the rapid expansion of the M23 armed group in eastern Democratic Republic of the Congo (DRC, DR Congo), particularly in North Kivu province and its spillover into neighboring South Kivu province. Briefing the UN Security Council on Monday, Bintou Keita, the UN special envoy to the DRC, described the situation as "one of the most serious, complex and neglected humanitarian crises of our times."