Pregnant women in Florida have been offered a free test to determine whether they have been infected with the mosquito-borne Zika virus.
State governor Rick Scott directed officials on Wednesday to make the tests available at county health departments.
He also said the state would provide additional lab services to handle the expected increase to ensure test results are processed quickly.
Health officials announced last Friday that mosquitoes have apparently started spreading the Zika virus on the US mainland, with a total now of 15 cases they strongly believe were caused by bites.
In an unprecedented warning, federal health officials directed pregnant women to avoid a Zika-stricken part of Miami.
The announcement on Wednesday comes as some doctors have complained they were being forced to ration test kits and turn away pregnant women who were requesting them.