(Bloomberg) -- Britain moved Canada and six other territories to its so-called green list, allowing travelers to skip quarantine regardless of their vaccination status, while holding off on tightening rules for arrivals from the U.S.

Denmark, Finland, Liechtenstein, Lithuania, Switzerland and the Azores will also be elevated to green status from 4 a.m. Monday, the Department for Transport said Thursday. Thailand will move to the red category as low vaccination levels leave Asia vulnerable to new coronavirus variants, along with Montenegro.

The U.S. remains on the U.K. amber list, meaning fully vaccinated arrivals don’t need to isolate, even as rising infection rates in the world’s largest economy prompt the European Union to consider tighter curbs. American Express Global Business Travel said the reclassification of Canada is especially welcome with the country expected to reopen to fully vaccinated Brits next month, something the Biden administration has yet to do.

“Today’s addition of Canada to the green list is a strong step forward for the safe return of bilateral transatlantic travel,” Andrew Crawley, the unit’s chief commercial officer, said in an emailed statement.

IAG SA’s British Airways said it was disappointed the U.K. hadn’t shifted ground on requiring pricey PCR tests, despite world-leading inoculation rates. Chief Executive Officer Sean Doyle said there also needs to be an end to uncertainty fostered by frequent changes to the traffic-light system.

Manchester Airports Group CEO Charlie Cornish said the category changes will have a positive impact on options for people still planning vacations in the remaining days of the summer season, while pressing for a simpler and more affordable system to be introduced before a scheduled review on Oct. 1.

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