Geneva, SwitzerlandHEALTHVIRUSCHINAWHOThe World Health Organization criticised Wednesday China's "very narrow" definition of Covid deaths, warning that official statistics were not showing the true impact of the outbreak.

"We still do not have complete data," the WHO's emergencies director Michael Ryan told reporters.

"We believe that the current numbers being published from China under-represent the true impact of the disease in terms of hospital admissions, in terms of ICU admissions, and particularly in terms of deaths."

His comments came amid growing concern over China's steep rise in Covid infections since Beijing last month abruptly lifted years of hardline restrictions, with hospitals and crematoriums quickly overwhelmed.

Yet China has only recorded 22 Covid deaths since December and has dramatically narrowed the criteria for classifying such fatalities -- meaning that Beijing's own statistics about the unprecedented wave are now widely seen as not reflecting reality.

"We believe that definition is too narrow," Ryan said, pointing out that the definition Beijing is using "requires a respiratory failure" associated with a Covid infection for a fatality to be registered as a Covid death.

"That is a very narrow definition."

He stressed that it was vital to have accurate information about how the virus was spreading and the true impact it was having, and he suggested that individual health professionals could help provide a more accurate picture.

"We do not discourage doctors and nurses reporting these deaths and these cases. We have an open approach to be able to record the actual impact of disease in society."

He recognised that China had stepped up its engagement with the WHO in recent weeks, and said "we look forward to receiving more comprehensive data."

WHO chief Tedros Adhanom Ghebreyesus told reporters that the organisation's officials had held high-level talks in recent weeks with counterparts in China.

"We continue to ask China for more rapid, regular, reliable data on hospitalisation and deaths, as well as more comprehensive, real-time viral sequencing," he said.

"Data remains essential for WHO to carry out regular, rapid and robust risk assessments of the current situation and adjust our advice and guidance accordingly," he said.

He reiterated that the UN health agency understood why a number of countries were introducing fresh Covid curbs on visitors from China.

"With circulation in China so high and comprehensive data not forthcoming... it is understandable that some countries are taking steps they believe will protect their own citizens," he said.