Vietcombank sold the dollar at VND23,900, up 0.17% from Tuesday.
The State Bank of Vietnam (SBV)’s reference rate was at VND23,773, up 0.07%.
The dollar has gained over the dong by 0.72% since the beginning of the year.
The dollar fell 0.08% to VND23,700 on the black market.
Globally the dollar struggled to make headway on Wednesday after a cut on the U.S. government’s top credit rating by Fitch raised questions about the country’s fiscal outlook, though it drew some support from a relatively resilient run of economic data, Reuters reported.
Rating agency Fitch on Tuesday downgraded the United States to AA+ from AAA in a move that drew an angry response from the White House and surprised investors, coming despite the resolution two months ago of the debt ceiling crisis.
That nudged the greenback lower, lifting the euro toward $1.10. The single currency was last 0.11% higher at $1.0996, after earlier touching a session-high of $1.1020.
Sterling similarly gained 0.05% to $1.2782, while the U.S. dollar index was last 0.09% higher at 102.09, after slipping broadly in the wake of the Fitch news.
"We don’t think the Fitch decision is that material. Certainly, we’ve seen the market move a little bit this morning ... but over the near term, I don’t think it’s going to be a longer lasting driver," said Rodrigo Catril, senior currency strategist at National Australia Bank.