The warning has a lower emergency rate than the previous one, when the CDC recommended pregnant women avoid nearly 60 countries and territories worldwide.
The Zika virus is transmitted to humans primarily through Aedes aegypty mosquito bites and sexual intercourse.
The symptoms of Zika infection include fever, conjunctivitis, headaches and muscle pains. Zika infection during pregnancy may lead to microcephaly in babies, which is responsible for incomplete brain development and an unusually small head.
A vaccine for the Zika virus has yet to be discovered.
Thailand has the most reported Zika cases in Southeast Asia with 349 cases since January 2016, including 25 pregnant women.
