Vietcombank sold the dollar at VND25,020, up 0.08% from Tuesday.
The greenback slid 0.4% to VND25,200 at unofficial exchange points.
The State Bank of Vietnam lowered its reference rate by 0.05% to VND24,212.
Since the beginning of the year, the dollar has increased against the dong by 2.46%.
Globally, the U.S. dollar held near its lowest level in more than a year against a basket of peers on Wednesday, with sterling trading just off multi-year highs, as markets focused on clues to the size of a widely expected U.S. interest rate cut next month, Reuters reported.
The dollar index, which measures the greenback against a basket of currencies, was last 0.07% higher at 100.67, hovering above a 13-month low of 100.51 hit in the previous session.
For the month, the dollar has fallen over 3%, putting it on track for its biggest monthly decline since November 2022.
Sterling ticked down slightly to $1.3250 after hitting its highest since March 2022 against the greenback at $1.3269 on Tuesday.
The euro slid 0.09% to $1.117375 and was sitting not far from a 13-month peak touched at the top of the week.
The yen seemed to largely brush aside the remarks as it edged 0.26% lower to 144.33 per dollar, off Monday's three-week high of 143.45 against the greenback.