World Health Organization notes 50 of the 53 countries and territories in its European region have reported the variant, as it calls for indoor mask mandate and speedy vaccinations.
More than half of people in Europe are on track to contract the Omicron coronavirus variant in the next two months if infections continue at current rates.
Speaking at a press conference on Tuesday, the World Health Organization (WHO) Regional Director Hans Kluge warned that the Omicron variant represented a "new west-to-east tidal wave sweeping across" the European region.
"At this rate, the Institute for Health Metrics and Evaluation (IHME) forecasts that more than 50 percent of the population in the region will be infected with Omicron in the next six to eight weeks," Kluge told reporters.
He said there were more than seven million new cases of the Omicron variant across Europe in the first week of January, more than doubling in just two weeks.
“Omicron moves faster and wider than any (previous) variant we have seen,” he said.
Kluge called for countries to mandate the use of masks indoors and to prioritise vaccination, including booster doses, of at-risk populations, including health workers and older people.
WHO’s Geneva headquarters has previously pleaded with rich countries not to offer booster doses and to donate them instead to poorer countries where vulnerable groups have yet to be immunised.
WHO's European region comprises 53 countries and territories including several in Central Asia, and Kluge noted that 50 of them had confirmed cases of the Omicron variant.
According to the WHO, 26 of those countries reported that over one percent of their populations were "catching Covid-19 each week", as of January 10.
Referencing data collected over the last few weeks, Kluge said the variant was confirmed to be more transmissible.
The "mutations it has enable it to adhere to human cells more easily, and it can infect even those who have been previously infected or vaccinated", he said.
However, Kluge also stressed that "approved vaccines do continue to provide good protection against severe disease and death, including for Omicron".
The highly transmissible variant has ripped through countries at breakneck pace, forcing governments to impose fresh measures and scramble to roll out booster shots.
Europe has been at the epicentre of alarming new outbreaks — hospital admissions and deaths are creeping up as well.