The Food and Drug Administration has given preliminary approval for the first test that can confirm a diagnosis of the Zika virus without multiple tests.
The faster test, created by the Centers for Disease Control and Prevention (CDC), was approved for emergency use on Thursday.
Diagnosing the Zika virus has been one of the toughest early challenges for countries battling the disease. There is still no widely available test for the virus, which is spreading rapidly across Central and South America.
The new CDC test will determine whether a person is infected with Zika or similar diseases chikungunya or dengue. All three are spread by mosquitoes.
While Zika is not life-threatening to adults, it has been linked to a birth defect called microcephaly, which causes babies to be born with abnormally small heads.