The Food and Drug Administration says it wants all blood centers in the U.S. to start screening for Zika.
Health officials say the decision was made to help protect the country's blood supply from the mosquito-borne virus.
The rule is already in effect for Puerto Rico and parts of Florida.
The Centers for Disease Control says there are nearly 30 cases of mosquitos transmitting the virus in the U.S. so far.
Testing is underway for a vaccine, but experts say the soonest it would be ready is next year.