Before any international traveler enters the United States, they will now be required to present proof of a negative coronavirus test. The new Centers for Disease Control and Prevention (CDC) policy takes effect on January 26.
"Testing does not eliminate all risk," Dr. Robert R. Redfield, the director of the CDC, said in a statement Tuesday. "But when combined with a period of staying at home and everyday precautions like wearing masks and social distancing, it can make travel safer, healthier, and more responsible by reducing spread on planes, in airports, and at destinations."
A passenger must get a viral test within three days of their flight to the U.S., providing either documentation of test results or proof of recovery from the virus to the airline. Airlines are required to deny any passenger who does not adhere to these guidelines.
A negative test is required for all passengers, regardless of whether or not they have been vaccinated. It is not yet clear whether vaccination prevents transmission of the virus.
The CDC said that testing before and after air travel is critical to slowing the spread of COVID-19. It cited the possibly more infectious variants of COVID-19 and the surging cases in the U.S. as evidence for stricter travel limitations.
"This strategy is consistent with the current phase of the pandemic and more efficiently protects the health of Americans," it said.
The CDC also recommends getting tested again three to five days after travel, as well as isolating at home for seven days.
Tighter travel restrictions come as a variant of the disease has been detected in several U.S. states. The new travel policy expands upon a similar one introduced specifically for U.K. passengers late last month.
As of Wednesday, the U.S. has had more than 22 million cases of COVID-19, and more than 375,000 deaths, according to Johns Hopkins University.
This article was originally published on CBSNews.com on Jan. 13.