The World Health Organization (WHO) warns against the spread of Zika virus in South, Central and North America.
The mosquito-borne virus is already present in 21 of the 55 countries and territories across the Americas, the organization said in a statement Sunday.
However, the UN public health arm said the carrier Aedes aegypti mosquito, which transmits Zika and also dengue and chikungunya viruses, is already present in all countries in the Americas, except Canada and Chile.
According to the WHO, about ten countries in Africa, Asia and the Pacific have reported cases of the mosquito-borne Zika virus infection.
The Zika virus is suspected to cause serious birth defects.
It is linked to microcephaly disease, in which babies born to women infected during pregnancy have abnormally small heads.
There is no sure prevention or treatment for the disease and affected countries are reportedly doing their best to eliminate the breeding grounds for mosquitoes.
The Aedes aegypti mosquito bites all day long.
The WHO said the best known prevention measures include wearing long sleeves and trousers, applying insect repellents and sleeping under mosquito nets.
At this point, no specific travel advisory has been issued by the WHO, but national centers could issue travel advice to their own nationals, based on the evidence they have.
Zika virus was first isolated from a monkey in Zika Forest, Uganda, in 1947.
In Brazil, three people were reported dead due to the Zika virus in November 2015.