The Centers for Disease Control says all international travelers, including Americans, must test negative for COVID-19 before boarding a flight to the U.S.

The new restrictions take effect Jan. 26. Air passengers are required to get a viral test within the three days before their flight to the U.S, and then, they must provide written documentation of the test results.

The airlines must then confirm the negative test result before they board. If a passenger does not provide documentation of a negative test, the airline is supposed to not let them get on the flight.

The CDC also recommends travelers get tested three to five days after returning to the states.