In the update of its Asian Development Outlook released on December 12, the bank said inflation rate in Vietnam is expected to hit 4% in 2018 and 4.5% next year.
The bank maintained its 2018 and 2019 economic growth estimates for Asia at 6.0% and 5.8%, respectively.
The ADB also kept its 6.6% and 6.3% growth projections for China as well as its 7.3% and 7.6% growth expectations for India for both years.
Early this month, US President Donald Trump and Chinese counterpart Xi Jinping agreed on a 90-day truce on further tariffs as they try to negotiate a deal.
But while the truce was a welcome development, ADB Chief Economist Yasuyuki Sawada said "the unresolved conflict remains to be the downside risk to economic prospects in the region."
The 2019 growth outlook for Central Asia was raised to 4.3%, from the September projection of 4.2%, the ADB said, but the forecasts for Southeast Asia and South Asia for next year were lowered to 5.1% and 7.1%, respectively.
Lower international commodity prices and central bank action to calm market volatility means inflation in developing Asia is forecast to be 2.6 percent in 2018 and 2.7% in 2019, down from 2.8% previously forecast for both this year and next year, it said.