The head of the World Health Organisation says he hopes the coronavirus pandemic will be over in two years, Sky News reports.

The Spanish flu pandemic of 1918 took two years to end, he said.

"Our situation now with more technology, of course with more connectiveness, the virus has a better chance of spreading, it can move fast," Tedros Adhanom Ghebreyesus said.

"At the same time we have the technology and knowledge to stop it."

More than 22 million people have tested positive for coronavirus globally and nearly 800,000 people have died, according to a tally by Johns Hopkins University.

Tedros warned that while some countries have managed to drive down transmission of COVID-19, "progress does not mean victory".

He pointed to several countries which are experiencing fresh outbreaks after long periods with little or no cases, such as New Zealand and Vietnam.