The U.S. State Department announced a global Level 4 travel advisory Thursday, instructing all Americans abroad to come home or shelter in place and stop all international travel.

It's the most severe warning from the federal government yet as coronavirus continues to spread – in the U.S. and abroad. The State Department already issued a global level 3 travel advisory, urging Americans to reconsider international travel. Level 4 is the State Department's highest warning, typically reserved for war-torn countries like Iraq and Afghanistan.

The new, more severe advisory comes as dozens of countries have blocked foreign travelers from entering. The European Union has imposed a 30-day ban on foreign travelers, as have Australia, New Zealand, and others.

Read all our coverage of the coronavirus outbreak and how it's affecting travel.

Meanwhile, airlines in the U.S. and across the globe have cut most – if not all – international flights. For example, Delta has cut 80% of its international service. American Airlines is operating just three international routes. Australia's Qantas is halting international flights altogether.

As the ability to fly home shrinks by the day, the government warned travelers to return while they can.

“In countries where commercial departure options remain available, U.S. citizens who live in the United States should arrange for immediate return to the United States, unless they are prepared to remain abroad for an indefinite period,” the advisory says. “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.”

 

This is a breaking news story. Check back for more updates.