Vietcombank sold the dollar at VND23,980, up 0.04% from Sunday.
The State Bank of Vietnam maintained its reference rate at VND23,897.
The dollar fell 0.04% to VND24,000 on the black market.
The dollar has increased over the dong by 1.05% since the beginning of the year.
Globally the dollar began on a firm footing on Monday, following five straight weeks of gains, as investors looked ahead to the Federal Reserve's Jackson Hole symposium for a guide on where rates might settle when the dust of this hiking cycle clears, Reuters reported.
The dollar made a gain of 0.7% on the euro last week, inched ahead on the yen and surged by more than 1% on the Antipodean currencies as U.S. Treasury yields leapt in anticipation of interest rates staying higher for longer.
The yuan slid to the weak side of 7.3 per dollar despite a firm fixing of its trading range by the central bank. It last traded at 7.3011, though so far keeping off last week's lows beyond 7.31, as that had brought state banks into spot markets in London and New York hours as buyers.