Vietcombank sold the dollar at VND24,700, down 0.04% from Thursday.
The State Bank of Vietnam lowered its reference rate by 0.04% to VND24,110.
The dollar fell 0.04% to VND24,630 on the black market.
It has increased against the dong by 4.09% since the beginning of the year.
Globally the dollar was within a hair's breadth of the closely watched 150 yen level on Friday, buoyed by a surge in the U.S. 10-year Treasury yield which in the previous session briefly reached 5% for the first time since 2007.
"The move up has been driven by the Fed leaving the market as a price insensitive buyer. Foreign demand has also waned. Combined with surprisingly large issuance from the deficit, it's a classic supply and demand effect," said Brian Jacobsen, chief economist at Annex Wealth Management.
That kept pressure on the yen, which last bought 149.83 per dollar , not far from the psychological threshold of 150 per dollar which some traders bet could trigger an intervention from Japanese authorities, as happened last year.