Although Covid deaths have dropped across the world, numbers could rise as northern countries head into winter, according to the UN health agency.

"We are now seeing a welcome decline in reported deaths globally. However, with colder weather approaching in the northern hemisphere, it is reasonable to expect an increase in hospitalisations and deaths in the coming months," World Health Organization chief Tedros Adhanom Ghebreyesus said Wednesday.

"Subvariants of Omicron are more transmissible than their predecessors, and the risk of even more transmissible and more dangerous variants remains."

Vaccination coverage among the most at-risk groups – such as health workers and older persons – also remains too low, especially in poorer countries, Tedros said.

"Living with Covid does not mean pretending the pandemic is over. If you walk in the rain without an umbrella, pretending it is not raining will not help you. You will still get wet. Likewise, pretending a deadly virus is not circulating is a huge risk," he said.

Read: Bangladesh’s Covid-19 death toll stands at 2,668

Worldwide, nearly 600 million cases of Covid have been recorded, some 2.5 years into the pandemic.

Europe is projected to reach 250 million cases in a matter of weeks, Dr Hans Kluge, director of the WHO's Office for the region, said. Like Tedros, he also anticipates the "winter surge" in cases.

"We have made great strides in addressing the pandemic. But the virus is still circulating widely, still putting people in hospital, still causing too many preventable deaths – some 3,000 in the past week alone, about a third of the global recorded total," Kluge said.