Israel says it will ban the entry of all foreigners into the country, making it the first nation to shut its borders completely in response to a new and potentially more contagious coronavirus variant.

Prime Minister Naftali Bennett said the ban, pending government approval, would last 14 days.

Officials hope within that period there will be more information on how effective COVID-19 vaccines are against Omicron, which was first detected in South Africa and has been dubbed a "variant of concern” by the World Health Organization.

"Our working hypotheses are that the variant is already in nearly every country,” Interior Minister Ayelet Shaked told N12’s Meet the Press. "And that the vaccine is effective, although we don’t yet know to what degree.”

The ban will come into effect at midnight on Sunday. A travel ban on foreigners coming from most African states was imposed on Friday.

Dr Ran Balicer, head of the government’s advisory panel on COVID-19, told Israel’s Kan public radio the new measures were necessary for the "fog of war” surrounding the new variant, saying it was "better to act early and strictly” to prevent its spread.

On Saturday, Israel said it detected the new strain in a traveller who had returned from Malawi and was investigating seven other suspected cases. The seven people included three vaccinated individuals who all were placed in isolation.

‘All this uncertainty’

"The entry of foreign nationals into Israel is banned except for cases approved by a special committee,” the prime minister’s office said in a statement.

Israeli citizens will be required to present a negative PCR test and quarantine themselves for three days if they have been vaccinated against the coronavirus and seven days if they have not. It was only four weeks ago that Israel reopened its borders to foreign tourists after a prolonged closure because of COVID.

Al Jazeera’s Harry Fawcett, reporting from West Jerusalem, called the new measures "extremely stringent” and said they marked a major reversal of a policy that allowed in foreign tourists at the beginning of November.

"They are the result of a late night emergency meeting of the coronavirus cabinet, which took place on Saturday evening after a brief announcement from Naftali Bennett that Israel needed to act very quickly in the midst of all this uncertainty and not risk the progress already gained against the coronavirus.”

The new measures will also require all Israelis entering the country, including those who are vaccinated, to quarantine.

Fawcett said Israelis who are vaccinated will have to quarantine for a minimum of three days, while those who are unvaccinated will have to quarantine for seven days.

He added, "And if coming back from one of the newly red-listed African countries, they will have to go into a government quarantine hotel, until they test negative.”

Separately, Bennett said the Shin Bet counterterrorism agency’s phone-tracking technology will be used to locate carriers of the new variant to curb its transmission to others.

Used on and off since March 2020, the surveillance technology matched virus carriers’ locations against other mobile phones nearby to determine with whom they had come into contact.

Israel’s Supreme Court this year limited the scope of its use after civil rights groups mounted challenges over privacy concerns.

The variant – which has also been detected in Belgium, the Netherlands, Botswana, Hong Kong, Italy, Germany, and the United Kingdom – has sparked global concern and a wave of travel curbs, although epidemiologists say such restrictions may be too late to stop Omicron from circulating globally.

About 57 percent of Israel’s 9.4 million population is fully vaccinated, according to the health ministry, which means they have either received a third shot of the Pfizer/BioNTech vaccine or it has not yet been five months since they received their second dose.

Israel has recorded 1.3 million confirmed cases of COVID-19 and more than 8,000 fatalities since the pandemic began.

Scientists in South Africa said on Thursday they detected the new B.1.1.529 variant with at least 10 mutations, compared with two for Delta or three for Beta.

The strain was of "serious concern” and was blamed for a surge in infections, authorities in South Africa said.