Beginning next week, all travellers to the US, regardless of nationality or vaccination status, will need to provide proof of a negative COVID-19 test within one day of boarding flights. That compares with three days now for those who have been vaccinated. The requirement is part of a larger package of domestic protocols aimed at stopping the spread of the Omicron COVID-19 variant.

The White House has shelved tougher options such as requiring post-arrival testing or requiring quarantines upon arrival in the US.

The White House has not yet acted to require domestic US travellers to be vaccinated or get tested. Officials believe such a requirement would be mired in litigation.

“We base our decisions on the advice of the health and medical experts, what’s going to be most effective and what we can implement,” press secretary Jen Psaki said Thursday.

President Joe Biden is extending his directive requiring masks on airplanes and other public transit, which had been set to expire in January, through at least the middle of March, the White House said.

US Travel said it hoped the shorter testing window would only be temporary until more is known about the variant, stating, ““It has long been known that measures to combat the virus and its variants would evolve and require us to be nimble and adapt.”

In the meantime, US Travel Association exec Tori Emerson Barnes said “the travel industry urges everyone to get vaccinated and boosted as soon as possible.”