Japan announced that it will suspend entry of all foreign visitors into the country as a new COVID-19 variant spreads.
Prime Minister Fumio Kishida said the measure will take effect from Tuesday.
The decision means Japan will restore border controls that it eased earlier this month for short-term business visitors, foreign students and workers.
Over the weekend, Japan tightened entry restrictions for people arriving from South Africa and eight other countries, requiring them to undergo a 10-day quarantine period at government-designated facilities.
Many countries have moved to tighten their borders after the new omicron variant of the coronavirus was found in a number of nations.
The variant was identified days ago by researchers in South Africa, and much is still not known about it, including whether it is more contagious, more likely to cause serious illness or more able to evade the protection of vaccines.