Vietcombank sold the greenback 0.32% higher at VND25,420.
The State Bank of Vietnam hiked its reference rate by 0.12% to VND24,425.
The dollar gained 0.63% to VND25,710 on the black market.
Globally the U.S. dollar slumped to an eight-week trough to the yen and lingered near a one-month low versus sterling on Thursday, as investor nerves about an inflation-stoking global trade war abated, Reuters reported.
The dollar sank 0.5% to 151.81 yen, the lowest since December 12, adding to a 1.1% slide on Wednesday.
The dollar index - which measures the U.S. currency against the euro, sterling, yen and three other major peers - stood at 107.57, not far from its overnight low of 107.29.
The index had jumped to a three-week high of 109.88 at the start of the week as Trump looked poised to impose 25% import tariffs on Mexico and Canada, but the countries won last-minute, one-month reprieves - although Washington did slap 10% tariffs on China.