PARIS - France has launched a battle to contain highly infectious variants of COVID-19 by reinforcing border control, ramping up tests and imposing mandatory 10-day quarantine for all arrivals from high-risk countries, where the new coronavirus strains are active, Prime Minister Jean Castex said on Sunday.

"We have launched the battle against these variants which are a threat against which we must protect ourselves," Castex told reporters at Roissy Charles-de-Gaulle airport.

Starting from Saturday, all arrivals from Chile, South Africa, Brazil, Argentina and India are subject to a strict 10-day quarantine. Prior to boarding on the plane, authorised travellers are required to present a negative polymerase chain reaction (PCR) test less than 36 hours old.

Only people residing in France or holding a French or European Union passport will be allowed to fly to the country, Castex said.

He noted that the coronavirus new strain, first detected in Brazil and South Africa, was behind "a few new cases" and "tends to regress" at home. But, "it's imperative to keep this trend, while developing vaccine rollout. That's the way out of this health crisis."

Data from health authorities released on Sunday showed that around 5.5 million COVID-19 cases have been confirmed in France and 102,858 deaths have been reported since the pandemic outbreak.

There are 30,287 patients treated in hospital, of whom 5,978 required life support, surpassing the country's initial capacity of 5,100 resuscitation beds.

To date, 14 million people in France have got at least one vaccine shot, representing 26.8 percent of the adult population, and over 5.5 million people have received the two jabs.

The French government aims to administer 20 million jabs by mid-May and to inoculate a total of 30 million, or two-thirds of the adults, by mid-June.