The World Health Organization insisted Monday that the international investigation into the Covid-19 pandemic's origins, set to start this week in China, was not looking for "somebody to blame".
WHO emergencies director Michael Ryan said the delayed mission -- finally given the green light by Beijing -- was about science, not politics.
Ten international experts will visit China from Thursday to probe the origins of the new coronavirus, more than a year after the pandemic began and amid accusations that Beijing has tried to thwart the investigation.
"Understanding the origins of disease is not about finding somebody to blame," Ryan told a press conference in Geneva.
"It is about finding the scientific answers about the very important interface between the animal kingdom and the human kingdom.
"It is an absolute requirement that we understand that interface.
"We are looking for the answers here, not culprits and not people to blame."
Experts say solving the mystery of how the virus first jumped from animals to humans is crucial to preventing another pandemic.
The mission will visit Wuhan in China, where the first cluster of cases was detected in December 2019.
The WHO had expected the investigation to start last week but, to the UN health agency's surprise and disappointment with two members already on their way, Beijing suddenly announced a last-minute hold-up over entry permission.
- Tedros plea for 'space' -
Following the disruptions and intense scrutiny, WHO director general Tedros Adhanom Ghebreyesus pleaded Monday for the mission to be given the space to do its work.
"We are pleased that an international team of scientists -- distinguished experts from 10 institutions and countries -- are commencing their travel to China to engage in and review scientific research with their Chinese counterparts on the origins of the Covid-19 virus," he said.
"Studies will begin in Wuhan, China to identify the potential source of infection of the early cases. Scientific evidence will drive hypotheses, which will then be the basis for further, longer-term studies.
"This is important not just for Covid-19 but for the future of global health security and to manage emerging disease threats with pandemic potential.
"Let's give this team of scientists the space to work with their Chinese counterparts effectively and let's wish them all well."
The novel coronavirus has killed nearly two million people since the outbreak first emerged in Wuhan.
"That milestone is a grim and shocking one as we do approach it," Ryan said.
At least 1.9 million people have died while more than 90 million cases have been registered, according to an AFP tally from official sources.
These figures are based on daily tolls provided by health authorities in each country and exclude later re-evaluations by statistical organisations.
Thousands of mutations in the virus have taken place as it has passed from person to person around the world.
New variants recently detected in Britain and South Africa are seemingly more contagious, though no evidence has emerged that they have increased the severity of any ensuing disease.
"Over the weekend, WHO was notified by Japan about a new variant of the virus," Tedros said.
"The more the Covid-19 virus spreads, the higher the chance of new changes to the virus. Most notably, transmissibility of some variants of the virus appears to be increasing," he explained.