The surge of petroleum imports from the East Asian country comes after a free trade agreement between the Association of Southeast Asian Nations (ASEAN) and South Korea came into effect in early 2016, lowering the import tariff on gasoline from 20% to 10%.
Meanwhile, petrol imports from traditional market China, which face a 20 percent tariff, witnessed an on-year decrease of 18% to 600,000 tons.
In total, Vietnam imported 7.55 million tons of petroleum worth $3.9 billion so far this year, marking a 34.2 percent jump in value from the same period last year.
Singapore remains Vietnam's the biggest petroleum supplier with 3.06 million tons. Petrol imports from ASEAN countries made up nearly 70 percent of Vietnam's total imports.
Vietnam exported around 1.2 million tons of petroleum in the first seven months, down 2 percent compared to the same period last year, mostly to Cambodia, Laos and China