BOGOTA, Colombia -- The World Bank says the spread of Zika will have a modest drag on the economy in the Western Hemisphere, with tourism-dependent Caribbean nations most at risk.

The Washington-based lender also said Thursday it was making available $150 million to assist in the fight against the virus.

Twenty-six nations and territories in the Western Hemisphere have reported outbreaks of Zika, which has been tied to a surge of rare birth defects in Brazil.

The World Health Organization has declared a global health emergency and the U.S. is urging pregnant women to avoid travel to affected areas. But the World Bank's report estimates the impact from the epidemic in terms of lost revenue will total only $3.6 billion or about 0.6 percent of the region's gross domestic product.