By David Shepardson
WASHINGTON (Reuters) - New rules requiring international air travelers arriving in the United States to obtain a negative COVID-19 test within one day of travel will take effect Monday at 12:01 a.m. ET (0501 GMT), according to an order issued late Thursday.
Under current rules, vaccinated international air travelers can present a negative test result obtained within three days of their day of departure. Unvaccinated travelers currently must get a negative COVID-19 test within one day of departure.
Centers for Disease Control and Prevention (CDC) Director Rochelle Walensky's order says the agency "must take quick and targeted action to help curtail the introduction and spread of the Omicron variant into the United States."
The CDC said beginning Monday "all air travelers, regardless of citizenship or vaccination status, will be required to show a negative pre-departure COVID-19 viral test taken the day before they board their flight to the United States."
The tighter testing timeline "provides an added degree of public health protection as scientists continue to assess the Omicron variant," the White House said in a factsheet released Thursday.
The CDC order noted the Omicron variant has been found in 23 countries. The order didn't require COVID-19 testing requirements for international travelers crossing U.S. land borders with Canada or Mexico.
CDC's order said it "may exercise its enforcement discretion to adjust the scope of accepted pre-departure testing requirements to allow passengers and airline and aircraft operators greater flexibility regarding the requirements."
The CDC is expected to give airlines a three-day grace period to allow for some travelers to return to the United States with tests taken outside of the one-day window, sources told Reuters.
The administration is considering whether to grant temporary exemptions for about two dozen countries where access to same-day testing is limited, but the details are still being finalized, the sources added. Those exemptions could last for only about a week and are expected to be detailed on Friday.
On Monday, the White House said it would bar nearly all foreign nationals from entering the United States from eight southern African countries over fears of the spread of the Omicron variant, but has not extended those travel restrictions to other countries where the new variant has been discovered.
The U.S. top infectious disease official Anthony Fauci said Wednesday he viewed the restrictions on the eight countries as a "temporary measure."
White House spokeswoman Jen Psaki said Thursday she would not "expect the lifting of restrictions before we know more about the variant. We will continue to evaluate if additional restrictions need to be put in place."
(Reporting by David Shepardson, Editing by Rosalba O'Brien & Shri Navaratnam)