The agency requested international tourism agencies to warn tourists, especially pregnant women, about risks when travelling to nations hit by Zika virus in Latin America.
The Zika virus has been linked to microcephaly, a condition that causes babies to be born with unusually small heads and in the vast majority of cases, brain damage.
As of February 25, the virus had circulated in 43 countries and territories, mostly in South America, the Caribbean and the Pacific Ocean. Vietnam has seen no cases so far.
