Vietcombank sold the dollar at VND24,740 Thursday, up 0.16% from Wednesday.
Eximbank sold the greenback at VND24,680, down 0.08%.
The State Bank of Vietnam raised its reference rate by 0.10% to VND24,041.
The dollar went up 0.04% to VND24,980 on the black market.
It has increased against the dong by 1.31% since the beginning of the year.
Globally the dollar held close to a one-month peak versus major peers on Thursday after robust U.S. retail sales data overnight added to building expectations the Federal Reserve will not rush to lower interest rates, Reuters reported.
Australia's dollar weakened after data showed an unexpected decline in employment.
The U.S. dollar index, which measures the currency against a basket of six rivals, traded little changed at 103.36 in the Asian morning, after reaching 103.69 on Wednesday for the first time since Dec. 13.