President Trump's decision to bar visitors from Europe has been followed by new restrictions in other nations. Here's a survey of which doors are being closed to travelers and where.
The United Kingdom's health minister has also been diagnosed with coronavirus – one of nearly 400 confirmed cases in that country, as Turkey on Wednesday announced its first case.
There are some 45,000 Americans working at U.S. military installations in South Korea and Italy. Both nations have major coronavirus outbreaks and travel to and from them is being restricted.
As the virus that causes the COVID-19 illness spreads around the world, governments have a chance to "break the chains of transmission," WHO Director-General Tedros Adhanom Ghebreyesus says.
"We have never before seen a respiratory pathogen that is capable of community transmission but which can also be contained with the right measures," the WHO's Tedros Adhanom Ghebreyesus said.
South Korea, Italy and Iran have each confirmed at least 10 deaths from the coronavirus disease COVID-19, a mark that surpasses the death toll reported in many Chinese provinces.
U.S. stocks fell sharply Monday as investors worried about a growing number of coronavirus infections outside China, and possible fallout for the global economy.