WASHINGTON—The Food and Drug Administration said late Monday that it will allow private companies to begin marketing coronavirus test kits directly to the public, in a new initiative to ease a chronic shortage of test kits.

The FDA said it will review the accuracy of test data submitted by the manufacturers retroactively—a decision that FDA Commissioner Stephen Hahn acknowledged had risks, but was warranted by the severity of the pandemic.

In a conference call with reporters Monday night, Dr. Hahn described the measures as a “flexible regulatory approach” intended to strike a balance between speed and the FDA’s regulatory oversight to achieve precision of tests.

Dr. Hahn said private companies that make the lab tests will need to file evidence of their accuracy with the FDA within about 15 days of release.

Dr. Hahn said the FDA said also will allow individual states to approve new diagnostic tests, as it already has done for New York. He said that the state initiative is designed to make state authorities act as a surrogate to the FDA during the current epidemic.