Anyone who does travel has been urged to get tested before and after their trips.
The winter surge in cases rages across the country, where the virus has claimed more than 320,000 lives and is on course to be the third leading cause of death in the year.
America reported more than 3400 deaths from the virus yesterday, and 232,000 new infections across the country.
California was the worst impacted with 44,000 new cases, followed by Texas (20,000), Florida (11,000) and New York (12,000).
AMERICANS START TO GET VACCINE
More than a million Americans have received the first dose of their COVID-19 vaccines, a milestone in the biggest immunisation drive in US history that came even as officials admitted the pace of rollout was slipping behind schedule.