Tourists pose for a selfie in flooded St. Mark’s Square in Venice, Italy, Thursday, Nov. 1, 2018 as rainstorms and strong winds have been battering the country. Two people were killed when a falling tree crushed their car in the mountainous countryside in northwestern Italy, as rainstorms and strong winds continued to pummel much of the country. (Andrea Merola/ANSA via AP)

The State Department has issued a rare global (level 4) health advisory. (Level four is the State Department’s highest.) This notice advises U.S. citizens to avoid all international travel to reduce the risk of infection from the coronavirus.

This advisory asks all U.S. citizens who are currently abroad to return home immediately unless they are willing to “remain abroad for an indefinite period.” And it asks those who live abroad to avoid all international travel.

The State Department warns:

Many countries are experiencing COVID-19 outbreaks and implementing travel restrictions and mandatory quarantines, closing borders, and prohibiting non-citizens from entry with little advance notice. Airlines have cancelled many international flights and several cruise operators have suspended operations or cancelled trips. If you choose to travel internationally, your travel plans may be severely disrupted, and you may be forced to remain outside of the United States for an indefinite timeframe.

If you decide to travel abroad or are already outside the United States:

* Consider returning to your country of residence immediately using whatever commercial means are available.

* Have a travel plan that does not rely on the U.S. Government for assistance.

* Review and follow the CDC’s guidelines for the prevention of coronavirus.

* Check with your airline, cruise lines, or travel operators regarding any updated information about your travel plans and/or restrictions.

* Visit travel.state.gov to view individual Travel Advisories for the most urgent threats to safety and security.

* Visit our Embassy webpages on COVID-19 for information on conditions in each country or jurisdiction.

* Visit the Department of Homeland Security’s website on the latest travel restrictions to the United States.

* Visit Keeping workplaces, homes, schools, or commercial establishments safe.

The full advisory can be viewed here.

This advisory comes as the number of deaths in Italy has exceeded the number in China. USA Today reports that as of Thursday, 3,405 Italians have died from the coronavirus. In the last 24 hours, 427 deaths were reported, according to Italy’s Civil Protection Department.

Secretary of State Mike Pompeo said the Department is working to get those who are stranded abroad home safely.