The UN agency on Friday expressed concern that the government's actions could block efforts to feed some 500,000 people in the impoverished Southeast Asian country.
According to the agency, Burmese authorities have stopped all movement of food out of the country's second-largest city, Mandalay, which will affect deliveries in northern Shan State.
Unrest also has stopped food delivery in the port city of Sittwe, disrupting the World Food Program's operations in north Rakhine State.
The U.N. agency says it is appealing to authorities for access to all parts of the country, to protect children, as well as HIV and tuberculosis patients.
