Countries including South Africa and Trinidad and Tobago have confirmed their first cases of Zika virus.
More than 5,000 pregnant women in Colombia have contracted the virus, its government has said.
The current Zika outbreak has been declared a "public health emergency of international concern" by the World Health Organisation.
Director-General Margaret Chan said that coordinated international action was needed to tackle to the current epidemic of the disease in South and Central America.
The WHO said there was not currently a public health justification for restrictions on travel and trade with affected countries.
However, action was needed to help prevent further infections and better understand the its potential effects including that on unborn babies.
The WHO said the emergency had been called not over Zika itself, but rather a cluster of serious brain defects in unborn babies and other neurological conditions thought to be caused by the virus infection.
Members of the WHO concluded the virus was "strongly linked" to babies born with microcephaly - a severe shrinkage of the brain - though the link has not yet been definitively scientifically proven.
The UN agency said last week the Zika virus was "spreading explosively" and could infect as many as 4 million people in the Americas.
Britain's camp for the Rio Olympics should be moved to a Zika-free location outside Brazil, Jessica Ennis-Hill's coach has said.
The mother of Zika "bucket baby" Jose Ferreira is holding out hope despite doctors' fears over his future.
The government has told airlines to take the measure on all flights travelling to the UK from countries with confirmed transmission of Zika.