The World Health Organisation (WHO) said on Tuesday that all available evidence suggests the novel coronavirus originated in animals in China late last year and was not manipulated or produced in a laboratory.
US President Donald Trump said last week that his government was trying to determine whether the virus emanated from a lab in the central Chinese city of Wuhan, where the coronavirus pandemic emerged in December.
"All available evidence suggests the virus has an animal origin and is not manipulated or constructed in a lab or somewhere else," WHO spokeswoman Fadela Chaib said in Geneva. "It is probable, likely, that the virus is of animal origin."
Ms Chaib said it was not clear how the virus had jumped the species barrier to humans but there had "certainly" been an intermediate animal host. "It most likely has its ecological reservoir in bats but how the virus came from bats to humans is still to be seen and discovered."
She did not respond to a request to elaborate on whether it was possible the virus may have inadvertently escaped from a lab. The Wuhan Institute of Virology has dismissed rumours that it either synthesised the virus or allowed it to escape.
Ms Chaib, asked about the impact of Mr Trump's decision last week to suspend funding to the UN agency over its handling of the coronavirus pandemic, said: "We are still assessing the situation about the announcement by President Trump ... and we will assess the situation and we will work with our partners to fill any gaps."
"It is very important to continue what we are doing not only for Covid-19 but for many, many, many, many other health programmes," she said, referring to action against polio, HIV and malaria among other diseases.
She said the WHO was 81 per cent funded for the next two years as of the end of March, referring to its US$4.8 billion (Dh17.63bn) biennial budget. The United States is the Geneva-based agency's biggest donor. Other big contributors are the Gates Foundation and Britain.