Travelers from nearly all parts of the United States will now have to spend three days of their two-week quarantine periods in government-designated facilities, as part of stricter quarantine requirements, the Japanese government said Wednesday.

The measure, effective Saturday, is part of strict border controls to prevent the spread of the Omicron variant of the novel coronavirus.

The three-day requirement previously only applied to travelers from a certain U.S. states. Travelers from New York and Hawaii will still be required to spend six days of their quarantine periods in the facilities, the government said.

Travelers from Ecuador, Lithuania, Russia and Slovakia will also have to spend three days of their quarantine periods in government-designated facilities.

Japan currently bans new foreign arrivals and requires returning Japanese nationals and foreign residents to quarantine in such facilities. Prime Minister Fumio Kishida has said the tighter rule would remain in force until early January.

Japan reported its first Omicron infection last month and the number of cases has continued to increase.

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