The United States is "very carefully studying" the possibility of issuing vaccination passports for travelers entering or leaving the country, National Security Secretary Alejandro Mayorkas said on Friday.

The department headed by Mayorkas oversees the Transportation Security Administration, which oversees the security of the country's transportation systems.

Mayorkas said in an interview with the ABC network that one of its guiding principles throughout the COVID-19 pandemic has been “the value of diversity, equity and inclusion and to ensure that any passport that is issued for vaccinations is accessible to all and that no one is excluded”.

The European Union, some Asian governments and the air transport sector are trying to create vaccination passports to boost international travel. They are trying to create systems that allow travelers to use applications on cell phones to prove that they are vaccinated and thus avoid being quarantined upon arrival.

The basis of everything, according to Mayorkas, is that "everyone should be vaccinated."