The stockpile will run from March to mid-April, the Vietnam Food Association said, which will affect Vietnam's biggest rice-producing region, the Mekong Delta.
Around 10.3 million tonnes of unhusked rice is expected to be produced in the Mekong Delta during this period, the Ministry of Agriculture and Rural Development said.
Export volume fell sharply in the first two months of this year and is predicted to remain low in the coming months due to weak demand in the global market and strong competition from other rice exporters, including Thailand, India and Myanmar.
A number of rice exporters have asked the government to boost exports to countries including China, Indonesia and the Philippines.
Vietnam plans to export 7 million tonnes of rice this year, up from 6.88 million tonnes, worth US$2.89 billion (94 billion baht) last year.