The International Monetary Fund said Vietnam's economy will expand 5.8 percent this year, revising down its previous forecast of 6.25 percent.
The country's economic growth is expected to speed up to 6.3 percent next year and then to 7.5 percent in 2016.
According to the IMF, Vietnam's inflation could hit 19 percent at the end of the year before easing to 8.1 percent in 2012. In its previous forcasts in June, the IMF said inflation would rise to about 13.75 percent by end-2011.
"Our assessment is basically that the priority for Vietnam should be on tackling very high inflation," Rupa Duttagupta, Deputy Division Chief, World Economic Studies Division, was quoted as saying in a transcript of an IMF press briefing.
Duttagupta said Vietnam's growth has been reasonably good, and monetary policy should continue to be on the tightening phase.
The fund also said increasing the pace of fiscal withdrawal is more urgent in economies with limited fiscal room and high public debt, and Vietnam is among those economies.
The world economy will expand 4 percent this year and next, the IMF said. The forecasts in June were 4.3 percent for 2011 and 4.5 percent for 2012.