The updated US intelligence briefing, published last week, said that a natural origin and a lab leak were both plausible hypotheses to explain how SARS-CoV-2, the virus responsible for COVID-19, first infected humans, but that the truth may never be known.
“The tracing of the origins of the novel coronavirus is a serious and complex issue that should and can only be researched through the cooperation of global scientists," he said.
China has consistently denied allegations that the virus was leaked from a specialist laboratory in the city of Wuhan, where COVID-19 was first identified at the end of 2019.