Vietcombank sold the dollar at VND24,430 Tuesday, up 0.12% from Monday.
The State Bank of Vietnam maintained its reference rate at VND23,870.
The dollar was stable at VND24,800 on the black market.
It has increased against the dong by 2.95% since the beginning of the year.
Globally the dollar was trying to find a floor on Tuesday in holiday-thinned trade, pressured by signs that inflation in the world's largest economy is cooling that will likely give the Federal Reserve room to ease interest rates next year, Reuters reported.
The yen meanwhile steadied near its recent five-month peak on the prospect that the Bank of Japan could soon mark an end to its ultra-easy policy. For most of 2022 and 2023, the policy has kept the Japanese currency under pressure as other major central banks globally embarked on aggressive rate-hike cycles.
The dollar index languished near a five-month low of 101.42 hit last week, and was last at 101.65.