The mosquito-borne virus has been linked to brain damage in infants, the New York Times reported.
The virus has affected Latin America and the Caribbean, and the World Health Organization (WHO) has warned the virus will likely reach nearly all of North and South America.
El Salvador has seen at least 5,000 cases of Zika, according to the paper. In Brazil, a million people have been infected and almost 4,000 children have been born with microcephaly, a condition that gives babies small heads and incomplete brain development.
The Centers for Disease Control and Prevention has advised pregnant women to avoid travel to places affected by the virus.