European countries must work harder to prevent the coronavirus spreading further as deaths and new cases surge, the World Health Organization's Europe head said on Thursday.

Current transmission rates in 53 European countries are of "grave concern" and new cases are nearing record levels, exacerbated by the more transmissible Delta variant of the virus, the WHO's Hans Kluge told a media briefing.

"We must change our tactics, from reacting to surges of COVID-19, to preventing them from happening in the first place," he said.

The region saw a 6% increase in new cases last week of nearly 1.8 million new cases, compared to the week before. The number of deaths rose 12% in the same period.

If the region follows its current trajectory, Kluge said, another 500,000 COVID-19 related deaths could occur in the region by February next year.

"Today every single country in Europe and Central Asia is facing a real threat of COVID-19 resurgence or already fighting it."