The Biden administration plans to tighten travel rules to combat the omicron variant of the coronavirus, by requiring all those traveling by air to the U.S. to be tested within a day of their departure regardless of vaccination status, according to a person familiar with the matter.

U.S. President Joe Biden plans to announce the new requirements Thursday in a speech detailing his plan to contain the pandemic through the winter. Currently, vaccinated travelers must get tested within three days of boarding their flight to the U.S.; under the change, that would be cut to one day.

Last week, the country imposed travel restrictions that bar arrival by foreign nationals who have been in any of eight southern African nations in the past 14 days. The administration hasn’t said how long those measures will be in place.