The White House is reportedly working on a plan to require all travelers arriving in the United States to present proof of COVID-19 vaccination.

According to The Associated Press, U.S. President Joe Biden is working on a process to ease travel restrictions for foreign citizens to the country, and the vaccination requirement is a cornerstone of the plan.

While no timetable has been announced, the government set up interagency working groups to study how and when to safely resume travel. Regardless of the exact details, mandatory vaccination protocols are expected for foreign visitors.

Last month, a White House official revealed the U.S. would not lift any existing travel restrictions in the foreseeable future due to concerns regarding the highly transmissible COVID-19 Delta variant.

All travelers entering the U.S. are currently required to show proof of a negative COVID-19 test taken within three days of air travel to the country.

Despite airlines and tourism officials heavily lobbying the White House for months to lift the restrictions, the Department of Homeland Security said land borders with Canada and Mexico would remain closed to non-essential travel until at least August 21.

The United Kingdom’s transport minister announced in July that fully vaccinated visitors from the European Union and U.S. would be allowed to skip COVID-related quarantine when visiting England.

While the U.S. is leaning toward vaccine mandates, the president of Mexico announced on Monday that his country has no plans of asking residents and arriving tourists for proof of COVID-19 vaccination.