UN Secretary-General António Guterres, during his visit to the Rohingya refugee camps in southern Bangladesh, vowed to do everything in his power to prevent further hardship as drastic aid cuts threaten food supplies and other critical relief efforts. UN aid efforts are in jeopardy following funding reductions announced by major donors, including the United States and several European nations.

Mr. Guterres described Cox’s Bazar as “ground zero” for the impact o...