Australia, Taiwan and South Korea advised pregnant women and those attempting to get pregnant to avoid travel to Singapore after an outbreak of the Zika virus infected more than 50 people in the city-state.
The outbreak and the warnings come as a potential blow to tourism in one of the world's busiest travel hubs, which is already struggling to recover from a slump amid tepid global growth.
Singapore reported its first case of locally-transmitted Zika at the weekend, and the number of reported infections of the mosquito-borne virus has since jumped to 56. At least three dozen of those have since made a full recovery.