The World Health Organization said Monday that Washington had provided no evidence to support "speculative" claims by the US president that the new coronavirus originated in a Chinese lab, ONA reports citing France 24.
"We have not received any data or specific evidence from the United States government relating to the purported origin of the virus -- so from our perspective, this remains speculative," WHO emergencies director Michael Ryan told a virtual briefing.
Scientists believe the killer virus jumped from animals to humans, emerging in China late last year, possibly from a market in Wuhan selling exotic animals for meat.
Top US epidemiologist Anthony Fauci echoed the WHO's statement in an interview published Monday evening by National Geographic.
"If you look at the evolution of the virus in bats and what's out there now, (the scientific evidence) is very, very strongly leaning toward this could not have been artificially or deliberately manipulated," Fauci told the magazine.
"Everything about the stepwise evolution over time strongly indicates that (this virus) evolved in nature and then jumped species," he said.
US President Donald Trump, increasingly critical of China's management of the outbreak, claims to have proof it started in a Wuhan laboratory.
And US Secretary of State Mike Pompeo on Sunday said "enormous evidence" backed up that claim, although the US intelligence community last week said it would continue to study whether the outbreak stemmed from infected animal contact, or a lab accident.
China has vehemently denied suggestions the lab was the source.
"Like any evidence-based organisation, we would be very willing to receive any information that purports to the origin of the virus," Ryan said, stressing that this was "a very important piece of public health information for future control.
"If that data and evidence is available, then it will be for the United States government to decide whether and when it can be shared, but it is difficult for the WHO to operate in an information vacuum in that regard," he added.