An international team of scientists led by the World Health Organization was set to arrive in the central Chinese city of Wuhan on Thursday to investigate the origins of the novel coronavirus that sparked the pandemic.
The United States, which has accused China of having hidden the extent of its initial outbreak a year ago, has called for a "transparent" WHO-led investigation and criticised the terms of the visit, under which Chinese experts have done the first phase of research.
Peter Ben Embarek, the WHO's top expert on animal diseases that cross to other species, who went to China on a preliminary mission last July, is leading the 10 independent experts, a WHO spokesman said.
Hung Nguyen, a Vietnamese biologist and part of the 10-member team, told Reuters that he did not expect any restrictions on the group's work in China, but cautioned against finding firm answers.
The team will spend two weeks in quarantine on arrival and two more weeks interviewing people from research institutes, hospitals and the seafood market in Wuhan where the new pathogen is believed to have emerged, Hung said.
The team would mainly stay in Wuhan, he told Reuters in an interview from Singapore on Wednesday.
Last week, WHO director-general Tedros Adhanom Gheybreyesus said he was "very disappointed" that China had still not authorised the team's entry for the long-awaited mission, but on Monday welcomed China's announcement of their planned arrival.
"What we would like to do with the international team and counterparts in China is to go back in the Wuhan environment, re-interview in-depth the initial cases, try to find other cases that were not detected at that time and try to see if we can push back the history of the first cases," Ben Embarek said in November.
China has been pushing a narrative via state media that the virus existed abroad before it was discovered in Wuhan, citing the presence of the coronavirus on imported frozen food packaging and scientific papers claiming it had been circulating in Europe in 2019.
"We are looking for the answers here that may save us in future - not culprits and not people to blame," the WHO's top emergency expert, Mike Ryan, told reporters this week, adding that the WHO was willing to go "anywhere and everywhere" to find out how the virus emerged.
Marion Koopmans, a virologist at Erasmus University Medical Center in the Netherlands and a member of the WHO-led team, said last month it was too soon to say whether the SARS-CoV-2 virus had jumped directly from bats to humans or had an intermediate animal host.
"At this stage what I think we need is a very open mind when trying to step back into the events that led eventually to this pandemic," she told reporters.