Vietcombank sold the dollar at VND24,675, down 0.16% from Monday.
The State Bank of Vietnam’s reference rate was 0.05% lower at VND24,023.
The greenback fell 0.28% to VND24,990 on the black market.
It has increased against the dong by 1.04% since the beginning of the year.
Asian currencies were up 0.1-0.4%, while the 10-year U.S. Treasury dipped, extending its decline from Monday. The U.S. Treasury Department said it would need to borrow less than its previous estimates, boosting demand for U.S. Treasuries.
The development precedes both the U.S. Treasury Quarterly Refunding Announcement and the U.S. Federal Reserve policy review scheduled for Wednesday, Reuters reported.
The dollar gave up 0.15% against the yen at 147.24 per greenback.
The euro was mostly unchanged at $1.0838.
Sterling was last trading at $1.2716, holding firm ahead of the Bank of England's monetary policy meeting this week.