The United States reached a new coronavirus pandemic recovery milestone on Monday; the White House ended its pandemic-era international travel ban that has been in place for more than a year and a half.

The ban--put in place by former President Donald Trump in early 2020 and later expanded by President Joe Biden earlier this year--prohibited foreign travelers from 33 countries, including the United Kingdom, much of Europe, China, Brazil and South Africa.

The U.S. is behind the recovery curve, as many European countries have already revised pandemic-era travel rules for international visitors, including U.S. citizens, earlier this year. The White House did not reopen its borders though, despite calls from airlines and other travel industry players for the U.S. to lift the ban.

Starting Monday, visitors can now fly into the U.S. with a few COVID health rules like vaccine requirements. All travelers will be required to provide contact information to their airline in case of an outbreak among passengers after their arrival to the U.S.

Here is what is required for international travelers seeking to enter the U.S. moving forward:

Proof of Vaccination

Under the new rules, non-citizens entering the U.S. will need to show proof of fully vaccination against COVID before their flight; the full vaccine regimen must be completed at least two weeks prior to departure.

Accepted vaccines under the rules are those approved or authorized for emergency use by the U.S. Food and Drug Administration and those endorsed by the World Health Organization. These include vaccines made by Pfizer (PFE  )-BioNTech (BNTX  ), Moderna (MRNA  ), Johnson & Johnson (JNJ  ), AstraZeneca (AZN  )-Oxford University, Sinopharm and Sinovac.

International travelers will need to submit proof of vaccine to airline personnel through paper certificate, a photo of the vaccine document or a digitized version.

COVID Diagnostic Test

In addition to full vaccination, the U.S. will also require proof of a negative COVID test within the past three days for all international travelers. The U.S. has already required a negative COVID test for all arriving travelers, including U.S. citizens, since the beginning of the year. Both rapid antigen and PCR tests will be accepted.

In cases where incoming travelers are not vaccinated, the COVID test must be taken within one day of their flight.

Exemptions to the Rules

Since many countries have yet to authorize vaccines for children, international travelers over the age of 2 are only required to show proof of negative COVID test--if they are traveling with vaccinated adults the test needs to be taken within three days of their flight, and if they are traveling alone the test must be taken within one day.

The U.S. has also eased requirements for travelers visiting from 50 countries that have low vaccine availability, including many nations in Africa, only requiring a negative COVID test. Also, visitors who cannot be vaccinated due to medical reasons will need to show an exemption letter from their medical professional to their airline.

U.S. citizens are not required to present proof of vaccination before departure, but will need to show proof of a negative COVID test within one day of their flight.