The move was because of fluctuation in the foreign exchange rate and because some fuel importers faced difficulties accessing credit from banks, the minister, Nguyen Hong Dien, told parliament.
"The domestic fuel market has been stable, without any shortage, while prices are comparatively lower than elsewhere in the region," he said.
Vietnam's fuel stocks of 3 million cubic meters are sufficient to meet domestic demand until the end of November, Dien added, while domestic refineries, which supply 70% to 80% of fuel needs, are running at full capacity.
Last week, the ministry said it had asked the central bank, the State Bank of Vietnam, to help local fuel traders access foreign currency to pay for fuel imports.
On Friday, the bank's governor, Nguyen Thi Hong, said the banking system had earmarked VND103 trillion ($4.15 billion) worth of loans for fuel trading firms, but they had taken just 58 trillion.
The central bank sold about $10 billion worth of foreign currency to fuel companies, including Vietnam's two refineries, in the first nine months, he added.
Vietnam's import demand for both 10-ppm sulphur and 500-ppm sulphur cargoes stayed strong, with Petrolimex still seeking three November arrival parcels after buying end-October parcels two weeks before, two Singapore-based traders said.
"There should be some stocking up in expectations of seasonal peak demand coming from north Vietnam as the region enters the winter season," a Singapore-based distributor said.
At least one cargo of 35,000 tonnes of 500-ppm sulphur gasoil was bound for north Vietnam from South Korea for October, Refeinitiv ship tracking data showed.
This week Vietnam's largest refinery, Nghi Son, said it would run at full capacity in the fourth quarter to ensure stable domestic supplies of petroleum products.
Binh Son, the other refinery, is operating at 109% of designed capacity, it said last week.