Vietcombank sold the dollar at VND24,750 Wednesday, up 0.08% from Tuesday.
The State Bank of Vietnam maintained its reference rate at VND24,030.
The dollar went up 0.08% to VND25,100 on the black market.
It has increased against the dong by 1.35% since the beginning of the year.
Globally the dollar hovered near a six-week high against major peers on Wednesday as investors cemented expectations that the Federal Reserve would be in no rush to cut interest rates in the face of a resilient U.S. economy, Reuters reported.
The Japanese yen, though, ticked higher as expectations rose for a stimulus exit as soon as March, following hawkish comments from the Bank of Japan on Tuesday.
The U.S. dollar index - which tracks the currency against six rivals, including the euro and yen - was flat at 103.48 after rising to the highest since Dec. 13 at 103.82 in the previous session.