In response to worries about a new coronavirus variation, the United States is going to require all air travelers entering the nation to produce a negative COVID-19 test completed within one day of departure, according to the Centers for Disease Control and Prevention (CDC) late Tuesday.

Currently, foreign flight travelers who have been immunized can provide a negative test result acquired within three days after their departure. To enter the United States, nearly all foreign nationals must be immunized. Unvaccinated tourists are presently required to get a negative COVID-19 test within one day of their arrival.

The new one-day testing requirement would be applicable to both US residents and international nationals.

Reuters previously reported that a draft proposal for the harsher testing requirement was circulating among government departments.

According to a CDC spokesperson, the agency is preparing to change its worldwide testing criteria for travel “when we learn more about the Omicron variant; a new order would decrease the timetable for necessary testing for all international air travelers to one day before departure to the US.”

Officials said the government is also evaluating whether to compel air travelers to take another COVID-19 exam within three to five days after arriving in the United States.

The CDC did not corroborate this, but stated that “all passengers should receive a COVID-19 viral test 3-5 days after arrival” and that “post-travel quarantine for all unvaccinated travelers” is still recommended.

The tighter guidelines were expected to be revealed on Thursday, although it was unclear when they would go into force.

The CDC, according to Director Rochelle Walensky, is “considering how to make foreign travel as safe as feasible, including pre-departure testing closer to the time of flight and thoughts surrounding further post-arrival testing and self-quarantines.”

Over fears about the Omicron strain, the White House blacklisted almost all foreign citizens who had recently visited South Africa and seven other southern African nations on Monday.

Earlier Tuesday, a White House source stated that the government is reviewing COVID-19 measures, “including adopting more severe testing requirements for overseas travel.”

The Centers for Disease Control and Prevention (CDC) warned Americans on Tuesday not to go to Niger, Papua New Guinea, Poland, or Trinidad and Tobago due to COVID-19 concerns.

The CDC currently classifies over 80 international places as having “Degree Four,” the greatest level of COVID-19 infection, and discourages Americans from visiting such locations.