In the U.S., health officials, including Dr. Anthony Fauci, say they're advising the White House not to impose travel restrictions against on the U.K. right now.
Some political leaders say that's a mistake.
"We have been victimized by federal incompetence and federal negligence. That is a fact," said New York Gov. Andrew Cuomo. "We're not going to be victimized again."
Virgin Atlantic, British Airways and Delta are the three major airlines that fly from the U.K. to New York. And they say they'll now test passengers on that route.
In Washington state, Gov. Jay Inslee says those coming from the U.K. or South Africa will have to quarantine for 14 days.