Joe Biden has vowed his administration will "declassify" as much information about the origins of COVID-19 as possible - including any potential links to a Chinese research lab.
Having ordered intelligence agencies including the FBI to investigate where the virus came from in 2021, the US president has now signed legislation that requires any details uncovered to be made public.
"We need to get to the bottom of COVID-19's origins to help ensure we can better prevent future pandemics," he said.
Mr Biden's bill, which he said would only limit the sharing of any information that "would harm national security", comfortably passed through both the Senate and House of Representatives.
Any relevant documents must be published within 90 days of the bill being signed.
It comes after FBI director Christopher Wray revealed the agency thought the virus "most likely" came from a Chinese laboratory leak.
He said Beijing - which has consistently rejected that assessment - was "doing its best to try to thwart and obfuscate" international efforts to learn more about the pandemic's origins.
More on Covid
COVID anniversary: Day of reflection across UK to mark five years since start of pandemic
COVID scars remain in the tight-knit communities of Welsh Valleys
