The deficit was $1 billion in January, $1.1 billion in February, $1.15 billion in March, $1.4 billion in April and $1.7 billion in May.
The May deficit saw a year-on-year increase of 17.3 per cent, said Le Thi Minh Thuy, head of the GSO's Trade Department.
"The deficit can be reduced with the decrease of imported goods and materials in favour of domestically produced equipment and materials and the support of local industry development," Thuy said.
During May, export value rose to $7.5 billion from $7.437 billion in April while the import value surged to $9.2 billion from $8.93 billion in April, she added.
Total export value during the first five months of this year saw a year-on-year increase of 32.8 per cent to $34.75 billion.
"The huge surge in export value during the first five months was mainly due to a sharp increase in world market prices, especially in terms of farm products, seafood, textiles and footwear, Vietnamese key exports," Thuy said.
Export value climbed by 113 per cent to $1.52 billion for rubber; 121.7 per cent to $1.77 billion for coffee; 109.4 per cent to $580 million for cassava and products made from cassava; 37 per cent to $2.98 billion for crude oil; 35.6 per cent to $5.1 billion for textiles and 31.8 per cent to $2.37 billion for footwear.
The state-owned sector saw a year-on-year growth of 31.1 per cent in terms of total export value during the first five months to $15 billion while the foreign investment sector saw a year-on-year growth in export value of 34.2 per cent to $19.01 billion.
High world market prices, while advantageous to export value, disadvantaged import activities because high prices pushed the total trade deficit up, Thuy said.
Total import value during the first five months increased 29.7 per cent compared with the same period last year to $41.33 billion.