A COVID-19 “tsunami” threatens to overwhelm health care systems, the WHO said Wednesday, as record surges fueled by the omicron variant dampened New Year celebrations around the world once again.

Governments are walking a tightrope between antivirus restrictions and the need to keep societies and economies open, as the highly transmissible variant drove cases to levels never seen before in the United States, Britain, France and Denmark.

The blistering surge was illustrated by AFP’s tally of 6.55 million new infections reported globally in the week ending Tuesday, the highest the figure has been since the World Health Organization declared a Covid-19 pandemic in March 2020.

“I am highly concerned that omicron, being more transmissible, circulating at the same time as Delta, is leading to a tsunami of cases,” said WHO chief Tedros Adhanom Ghebreyesus.

“This is and will continue to put immense pressure on exhausted health workers, and health systems on the brink of collapse.”

The variant has already started to overwhelm some hospitals in the United States, the hardest-hit nation where the seven-day average of new cases hit 265,427, according to a Johns Hopkins University tracker.