Vietcombank sold the dollar at VND24,650, up 0.08% from Monday.
The State Bank of Vietnam raised its reference rate by 0.02% to VND24,093.
The dollar went up 0.08% to VND24,640 on the black market.
It has increased against the dong by 3.88% since the beginning of the year.
The U.S. dollar started Tuesday on the back foot as investors took stock of developments in the Middle East and braced for a slew of speeches by central bank officials this week headlined by Fed Chair Powell to gauge the monetary policy outlook, Reuters reported.
The yen was pinned close to the key 150 per dollar level, keeping traders on edge for any signs of intervention by the Japanese authorities.
The yen last fetched 149.62 per dollar, having slipped to 150.17 on Oct. 3, the weakest in a year, before getting some relief in a brief rally.
The dollar index, which measures the U.S. currency against six rivals, eased 0.038% to 106.20, after dropping 0.36% on Monday.