The U.S. could deny migrants ⁠access to asylum on the grounds they present a public health risk under a newly finalized regulation drafted during the COVID-19 pandemic in President Donald Trump's first term.

The regulation, effective on Wednesday, allows U.S. authorities to bar asylum based on "emergency public ‍health concerns generated by a communicable disease," according to a copy ‍posted in the Federal Register on Monday.

The restrictions would not have any immediate effect but would provide the Trump ⁠administration with the ability to turn away would-be asylum seekers at the U.S.-Mexico border. The number of migrants caught crossing illegally dropped to the lowest levels in decades after Trump took office in January and implemented a sweeping asylum ban at the border.

When COVID-19 took root in 2020 during Trump's first term, his administration ‍used a U.S. health authority known as Title 42 to rapidly send migrants ⁠caught crossing the border back to Mexico, explaining it was needed to limit the spread of the virus. Former President Joe Biden, after assuming office in 2021, kept the Title 42 restrictions in place until 2023, partly due to legal ⁠challenges that stalled attempts to end it.

Advocates have criticized ⁠the use of health emergencies to broadly deny access to asylum, saying U.S. law has been ‍used to support Trump's efforts in curbing immigration.

"Considering the large amount of discretion the regulation grants ‌the administration and the president's hyperfixation on immigration enforcement, we can expect this new authority to be overused and abused," said Sarah Pierce, director of social policy ⁠at the center-left group Third Way.

The ‍Biden administration postponed the effective date of the regulation five times but did not take steps to terminate it.

In addition to ‍asylum, the measure also allows federal agencies to deny another form of protection known as "withholding of removal."