The move comes amid the steady climb in the price of most staple goods, including the doubling of the cost of cooking gas, which has put increasing strain on large numbers of Cambodians.
"Cambodia will halt the export of rice for two months," Hun Sen said.
"It is a temporary measure ... but it is to ensure food security," he added.
Rice prices have risen sharply from about 40 cents a kilogramme as speculation of shortages grip local markets, sparking demands that the government put a cap on costs.
But Hun Sen said Tuesday that Cambodia is experiencing a rice surplus, and blamed the price hike on "economic sabotage" -- people spreading rumours of dwindling rice supplies in a bid to undermine the government.
Despite GDP growth averaging 11 percent over the past three years, more than a third of the country's 14 million people live on less than 50 cents a day, making even the slightest rise of food costs devastating to Cambodia's poorest.
Petrol remains at record highs on the