A World Health Organization team in China to research the roots of COVID-19 had"extensive discussions" and exchanges with scientists in Wuhan in which the outbreak was first detected, a spokesman said on Tuesday.

The talks included updates on animal health study, he said. China shut down a wildlife market in Wuhan in the start of the outbreak, a day after discovering some patients were sellers or dealers.

The WHO says the virus most likely came from bats and likely had another, intermediary animal"host".

The Trump government resisted the WHO of being China-centric and plans to leave the agency over its handling of this pandemic.

The three-week advance assignment comprising two experts in animal health and epidemiology was tasked with laying the groundwork for a wider team of international experts that will want to discover the way the virus which leads to COVID-19 jumped the species barrier from animals to people.

Lindmeier did not provide details about the time or makeup of the wider mission.

Terms of reference to the broader mission have been generated together with Chinese authorities in draft form, '' he said, and weren't yet publicly available.

The team's composition is bound to be sensitive since any exception of US experts would be contentious. Another question will be the degree of access granted by Beijing.

US President Donald Trump and Secretary of State Mike Pompeo have stated the pathogen could have originated at a lab in Wuhan, although they've presented no evidence for this and China has denied it. Researchers and US intelligence agencies have said it emerged in character.

WHO emergencies chief Mike Ryan said on Monday that surprises were potential.

"The fact that that fire alarm was triggered (in Wuhan) does not necessarily indicate that is the point where the illness crossed from animals to individual," he explained.