Vietcombank sold the dollar at VND25,468, up 0.004% from Thursday.
The State Bank of Vietnam (SBV)’s reference rate increased by the same percentage to VND24,256.
At unofficial exchange points, the greenback fell 0.04% to VND25,840 on the black market.
It has increased against the dong by 4.29% since the beginning of the year.
Globally, the U.S. dollar pushed to a fresh eight-week top above 159 yen and clung close to a five-week peak to sterling on Friday, with the Federal Reserve's patient approach to cutting interest rates contrasting with more dovish stances elsewhere, Reuters reported.
Fed officials left policy unchanged at their June meeting, and shaved previous projections for three quarter-point cuts this year to one, even as inflation has cooled and the labor market has eased.
The dollar index was little changed at 105.66, on course for a slight weekly gain that would extend its winning streak to three weeks.
The dollar last traded 0.05% stronger at 159.015 yen.
The euro edged 0.06% higher to $1.0708, trying to recover from Thursday's 0.39% slide.