The dominoes fell quickly after South African health authorities informed the world of their discovery of the Omicron variant of the coronavirus in late November.
Things are changing by the day and even by the hour, but here are some of the questions people have about US travel rules — and answers we have as of December 2:
Are testing rules for entry into the US changing?
All inbound international travelers will be required to test within one day of departure for the United States starting Monday.
All flights departing after 12:01 a.m. ET December 6 will abide by a new CDC testing order, per an administration official.
President Joe Biden speaks about the Omicron variant during a visit to the National Institutes of Health in Bethesda, Maryland, on Thursday.
Currently, vaccinated travelers are required to test within three days of their departure. There is a requirement for foreign travelers arriving in the United States to be fully vaccinated.
Unvaccinated Americans and legal permanent residents are allowed to enter the country with a test taken within one day of departing for the United States. The new rule will make the testing time frame one day for everyone.
Biden also announced that the federal mask mandate requiring travelers to wear masks in airports, on planes and on other modes of public transportation such as trains and buses has been extended through March 18.
A Covid-19 test center operates inside the Tom Bradley International Terminal at Los Angeles International Airport on December 1.
Mario Tama/Getty Images
Is there a post-arrival testing or quarantine requirement?
There is not. “We’re not announcing any steps on post-arrival testing and quarantine,” a senior administration official said in a press briefing on Wednesday evening.
What countries fall under the new US travel ban?
The travel bans announced on November 26 bar entry into the US of noncitizens coming from eight countries in southern Africa. They are Botswana, Eswatini, Lesotho, Malawi, Mozambique, Namibia, South Africa and Zimbabwe.
Citizens of those nations and citizens of other nations who have been traveling there in the past 14 days are currently not allowed entry into the United States.
Can US citizens already in those nations return?
Yes they can.
As of December 2, they still had to follow the rules already in place to re-enter: A negative result from a Covid-19 test within three days of travel if fully vaccinated and within one day of travel if unvaccinated.
Can US citizens still travel to the banned nations?
At least two US carriers are still flying back and forth from South Africa, for example. Delta Air Lines is still offering Atlanta-Johannesburg service, and United Airlines is still offering Newark-Johannesburg service.
United Airlines is also resuming nonstop service between Newark and Cape Town, according to a news release from South African Tourism. The release also said, “we would like to emphasize that our country remains open for all those travelers who wish to visit.”
Whether it’s advisable to go is another matter. The CDC advises against it.
You might also encounter new travel barriers. For instance, Zimbabwe imposed a lockdown and mandatory quarantine on Tuesday, November 30, for travelers, state-run news agency NewZiana reported.
What is the US doing to detect the virus?
The CDC also confirmed to CNN on Wednesday that officials have directed airlines carrying passengers that have been to certain southern African nations to share those passengers’ contact information with the agency.
CNN Travel will update this article as new information becomes available and rules change. CNN’s Wayne Chang, Kaitlan Collins, Jacqueline Howard, Pete Muntean, Megan Vazquez and Greg Wallace contributed to this report.