The tariffs would "significantly damage" Vietnam's current export-based growth model, which heavily relies on exports to the United States, she said, adding in the worst-case scenario there could be a three percent hit to GDP this year.
According to data from the US Trade Representative website, the United States imported $136.6 billion worth of goods from Vietnam last year, representing nearly 30 percent of its GDP.
In the wake of the announcement, Hanoi shares tumbled, with its main index closing down 6.7 percent on Thursday, its biggest drop since 2001 according to Bloomberg.
- 'Can't eat, can't sleep' -
The tariffs have left workers in Vietnam fearing for their futures.
"I can't eat or sleep well because I keep worrying about losing my job," said 38-year-old Cao Thi Dieu, a worker at a factory in Ho Chi Minh City that makes shoes for brands such as Nike and Adidas.
"How will I manage if I lose my job? How will I continue earning money each month to take care of my two children's education?" she told AFP.