Japan has announced it will suspend entry of all foreign visitors due to the spread of the new coronavirus variant Omicron.

Prime Minister Fumio Kishida said the measure will take effect on 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 variant was found in a number of nations.

Omicron 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.

But many countries rushed to act, reflecting anxiety about anything that could prolong the pandemic that has killed more than five million people.