"This is a moral and scientific imperative," the WHO said in Geneva on Monday. "We continue to call on China to share data and access so we can understand the origins of COVID-19."
"Without transparency, sharing, and cooperation among countries, the world cannot adequately prevent and prepare for future epidemics and pandemics," the WHO warned.
Since the beginning of the pandemic, China had been concerned that it would be blamed for the global outbreak.
Since then, the government and state media have been pursuing a massive opinion campaign focusing on the possibility that the virus could have come from abroad and not from China.
It was not until 2021 that a joint commission of Chinese and WHO experts was able to travel to Wuhan.
In its final report, the commission considered it "probable to very probable" that the coronavirus originated from a wild animal species and then spread in another animal species before jumping to humans.
However, the origin and route of transmission could not be clearly identified.
In September, an international scientific study provided further evidence that COVID-19 originally came from wild animals traded at a market in Wuhan and that the virus did not escape from a laboratory in the central Chinese city.
According to the WHO, around 777 million cases and around 7 million deaths were reported worldwide since the outbreak of the disease.
However, the organisation assumes that the true number of people who have died directly and indirectly as a result of the pandemic is many times higher than the documented cases.
