The World Health Organization (WHO) has called on European countries to intensify coronavirus measures as the region deals with a new variant that was first detected in the UK.

WHO Europe director Hans Kluge said Thursday that further measures were needed to "flatten the steep vertical line" of rising cases in some countries.

While the variant appears to spread more easily than others, there's no evidence that it's any more deadly or causes more severe disease.

Health officials have also downplayed the possibility that coronavirus vaccines won't work against the variant.

But in the UK, health workers are struggling with a steep rise in cases and deaths. The country recorded a total of 1,041 further deaths on Wednesday, as well as 62,322 new cases. The crisis is particularly acute in London.

On Thursday mayor Sadiq Khan said the capital was at risk of running out of hospital beds in the next few days."This virus is out of control," Khan told LBC radio. "The [National Health Service] is on the cusp of being overwhelmed.

There has been no time during this pandemic where I've been more concerned than I am today."

Kluge, speaking during a news briefing Thursday, said the UK variant has now been detected in 22 countries across the WHO European region.

"It is our assessment that this variant of concern may, over time, replace other circulating lineages as seen in the United Kingdom, and increasingly in Denmark," Kluge said.

"With increased transmissibility and similar disease severity, the variant does, however, raise alarm: without increased control to slow its spread, there will be an increased impact on already stressed and pressurized health facilities."

"This is an alarming situation, which means that for a short period of time we need to do more than we have done and to intensify the public health and social measures to be certain we can flatten the steep vertical line in some countries," Kluge added.

Kluge then urged countries "to mitigate this burden by doing all they can to reduce transmission and increase vigilance to identify any new variants."

A number of European nations are currently under a lockdown or have 0imposed strict Covid-19 measures, including Britain, Italy, Germany Switzerland and Greece.