President Joe Biden said Thursday that travelers coming to the U.S. from abroad will also be required to quarantine upon arrival, in addition to the new testing requirements for international travel announced last week.

Biden laid out his additional requirements for international travel – both for visitors and returning citizens – as part of his latest executive orders since taking office just this week. Biden's actions will also make mandatory masks on flights and in airports a federal law, putting the muscle of the federal government behind policies U.S. airlines put in place last spring.

But adding quarantine requirements throws another wrench into international travel in and out of the U.S. It comes just over a week after outgoing President Trump's administration announced it would require travelers to present a negative COVID-19 test before boarding a flight to the U.S. That requirement is set to take effect Jan. 26.

It's unclear if the new quarantine requirements will also take effect next week, and how long travelers would be required to quarantine upon arrival. Biden's new COVID-19 response plan released Thursday says it will require travelers to “comply with CDC guidelines for self-isolation and self-quarantine upon arrival.” The CDC currently encourages travelers to self-isolate for at least seven days after travel – and at least 10 days without testing.

“Everyone flying to the U.S. will need to test before they get on that plane … and quarantine when they arrive in America,” Biden said from the White House on Thursday afternoon.

But the text of Biden's executive order raises more questions than answers, giving federal agencies plenty of wiggle room to reassess or change things. And it also leaves the door open to additional restrictions on domestic travel – something that hasn't happened in the U.S. to this point.
 

international travel quarantine 

It's also unclear how long these new restrictions for international travel will last. The new COVID-19 testing requirements are expected to last for many months – and as long as through the end of 2021.

Read up on everything you need to know about the new international travel testing requirements.

Enforcing quarantine requirements will be another issue. The U.S. has struggled with even rudimentary public health measures at airports like temperature checks and health screenings upon arrival from international flights. The Trump administration dropped those measures this fall.

Ensuring that travelers arriving from abroad comply with quarantine requirements would likely require a vast contact tracing program.