The United States will require all passengers arriving from the UK to have a negative coronavirus test within 72 hours of their departure, the Centers for Disease Control and Prevention said Thursday.
The move comes as a new highly transmissible variant of the virus, which first appeared in the UK, has led countries to seal their borders to travelers from there.
The new rule, which goes into effect Monday, applies to both Americans and foreign nationals and requires passengers to provide evidence of a negative result on a genetic test known as P.C.R. or antigen test is called.
“This additional testing requirement will strengthen our protection of the American public to improve their health and safety and to ensure responsible international travel,” said the C.D.C. said in a statement.
Passengers must provide the airline with “written documentation of their laboratory test results (in printed or electronic form)”, according to the C.D.C. said, adding that “if a passenger does not want to take a test, the airline must refuse the passenger to board.”
The new rules were a reversal for the Trump administration, which initially told American airliners that the government would not require testing for travelers from the UK.
United Airlines, Virgin Atlantic and Delta Air Lines had already announced similar guidelines requiring all passengers on their flights between the UK and the United States to provide evidence of a negative test result within 72 hours of departure. British Airways also requested negative test results for passengers arriving in New York.
Several of the airlines announced their policies after New York Governor Andrew M. Cuomo requested that passengers coming from London to John F. Kennedy International Airport must document a negative test result.
“We cannot allow history to repeat itself with this new variant,” said Cuomo had written on Twitter.
Also on Thursday, New Jersey Governor Phil Murphy said passengers arriving at Newark Airport would need negative tests within 72 hours of departure in order to enter.
American travel requirements are less draconian than those of other countries in Europe and Asia, which excluded all travelers from the UK after the advent of the new coronavirus variant. Experts are skeptical that travel bans can stop the variant from spreading. Dr. Anthony S. Fauci, the leading U.S. infectious disease expert, said there was a good chance the variant was already in the country.
“I don’t think such a draconian approach is necessary,” he said of a travel ban for PBS NewsHour. “I think we should think seriously about the possibility of requiring people to be tested before they come from the UK.”
A recent study by British scientists found no evidence that the variant was more lethal than others. However, the researchers estimated that it was 56 percent more contagious. The country also announced a travel ban from South Africa after Health Secretary Matt Hancock said two people were discovered with another variant that had surfaced in the African country. Another variant has also appeared in Nigeria.
The UK authorities this week put much of England under renewed restrictions on travel and socializing, warning that schools and universities may have to close soon.
Vivian Wang contributed to the coverage.