The United States is reopening its land and air borders to foreign visitors fully vaccinated against Covid-19, ending 20 months of restrictions on travel from around the globe that separated families, hobbled tourism and strained diplomatic ties.

Lifting the travel ban will affect more than 30 countries, but entry into the United States will not be totally unregulated: US authorities plan to closely monitor travellers' vaccination status and will still require them to present negative Covid-19 tests, according to an AFP report.

The United States will require air passengers to be fully vaccinated and be tested within three days before travel. Airlines will be required to put in place a contact tracing system.

The land border opening will happen in two phases.