The United States has said it will stop supporting United Nations logistical assistance for the African Union peacekeeping mission in Somalia from next year, a move that could jeopardise one of Africa’s largest and longest-running security operations.

According to diplomatic documents reviewed by Reuters, Washington informed the African Union that it would not support the continuation of the U.N. Support Office in Somalia (UNSOS) beyond the end of 2026.

The office provides critical logistical support, including food, fuel, medical services, transport and other operational assistance, to the African Union Support and Stabilisation Mission in Somalia (AUSSOM), which has nearly 12,000 personnel.

While the United States said it would not oppose renewing AUSSOM’s mandate at the U.N. Security Council, it said it would reject any extension that included continued U.N. logistical or operational support.

The decision comes as the administration of President Donald Trump reassesses U.S. spending on overseas security missions and argues that Somalia has made insufficient progress towards taking responsibility for its own security despite years of international assistance.