China rejects 'compromised' WHO plan for study of virus origin

Liang said it is key to investigate other countries and regions concurrently to better understand the early clinical cases, genetic sequence of the virus, as well as its methods of transmission including natural spillover, spread through intermediate host, and the role of cold-chain logistics.

"These are very complicated and difficult scientific questions that require solidarity and cooperation from scientists, governments and the public around the globe," he said.