Vietcombank sold the greenback 0.007% higher at VND26,362.
On the black market the dollar fell 0.29% to VND27,470.
Globally the dollar advanced against major currencies on Thursday, reversing two days of losses, after U.S. President Donald Trump's address on Iran shattered hopes for a possible ceasefire in the Middle East conflict that has rattled investors and roiled markets, Reuters reported.
The dollar index, which measures the greenback against a basket of currencies, climbed to a high of 99.925 after the speech. It last traded up 0.3% at 99.861.
The greenback has benefited from a rush to safe-haven assets since the conflict began in late February. Expectations that a ceasefire could be near have reversed some of the markets' most popular trades earlier this week and put the greenback on a two-day decline.
"Trump's comments failed to reassure markets ... markets are starting to realize that the war will probably escalate further from here before de-escalating," said Carol Kong, a currency strategist at Commonwealth Bank of Australia.