The World Health Organization's emergency committee will debate whether a Zika virus outbreak suspected of causing a surge in serious birth defects in South America should be considered a global health emergency.

More than 2,100 pregnant Colombian women are infected with the mosquito-borne Zika virus, the country's national health institute says, as the disease continues its spread across the Americas.

Brazilian President Dilma Rousseff vows to "win the war" against the Zika virus, but some experts criticized her government's response and warned the Olympics could fuel the disease's spread.

WHO Director-General Dr Margaret Chan said the virus — which has been linked to birth defects and neurological problems — was becoming much more of a threat.

Brazil President Dilma Rousseff has called on the whole of Brazilian society to help combat the spread of the Zika virus, which has been linked to birth defects.

The World Health Organization sets up a Zika "emergency team" after the "explosive" spread of the virus.

The Brazilian health ministry has confirmed a link between a mosquito-borne virus from Africa, Zika Fever, and a high incidence of birth defects.