The Omicron variant is "spreading at lightning speed" throughout Europe, according to French Prime Minister Jean Castex, and will likely become dominant in France by the start of next year.
He spoke on Friday, just hours before France placed stringent travel restrictions on British citizens entering the country.
With approximately 15,000 confirmed Omicron cases as of Friday, the UK has been the hardest struck in the region thus far.
Health experts across the continent are preparing for a wave of infections.
On Friday, administrations in Germany, the Republic of Ireland, and the Netherlands announced new restrictions in an attempt to stem the tide.
Germany's Health Minister Karl Lauterbach warned reporters that the country "must prepare for a problem that we have not previously encountered in this shape," after the country reported 50,000 new cases on Friday.
In Ireland, where the new variation is responsible for a third of new cases, Prime Minister of Ireland Micheál Martin predicted "infections at a rate well in excess of anything we have seen to yet."
Their statements came after the UK reported a record number of Covid infections for the third day in a row - over 93,000 - thanks mostly to Omicron.
France closed its border to tourists and businesspeople traveling from the United Kingdom on Friday, causing massive lines to build at the Port of Dover and Eurostar stations as passengers rushed to enter before the restriction took effect.
All official New Years Eve celebrations and firework displays have been cancelled.
Mr Castex added that the government would announce new steps to tackle vaccine hesitancy next year, saying it was "not acceptable that the refusal of a few million French people to be vaccinated puts the life of an entire country at risk".
