Vietcombank sold the dollar at VND25,190, up 0.28% from Thursday.
The greenback slid 0.2% to VND25,280 at unofficial exchange points.
The State Bank of Vietnam hiked its rate by 0.02% to VND24,250.
Since the beginning of the year, the dollar has risen by 3.15% against the dong.
Globally, the yen rose on Friday as traders considered comments from Bank of Japan Governor Kazuo Ueda, who sought to calm lingering nerves after a surprise rate hike last month, while markets braced for a speech from Federal Reserve Chair Jerome Powell, Reuters reported.
The dollar index, which measures the greenback versus six major peers, was 0.11% lower at 101.35 after rising 0.34% in the previous session but remains close to the 2024 low of 100.92 it touched on Wednesday. The index is headed for fifth straight week of losses.
The yen was 0.5% higher at 145.58 per dollar after Ueda reaffirmed his resolve to raise rates if inflation stayed on course to sustainably hit the 2% target, but warned financial markets remained unstable.
The euro was last 0.1% higher at $1.1124, not far from the 13-month high it touched on Wednesday, while sterling fetching $1.31015, just shy of the 13-month high it hit on Thursday.