US President Donald Trump said on Friday that he has terminated Washington's relationship with the World Health Organisation (WHO), accusing the United Nations agency of bowing to pressure from China and allowing the Covid-19 pandemic to spread out of control.

"We have detailed the reforms that [the WHO] must make and engage with them directly, but they have refused to act," Trump said in a White House press briefing. "Because they have failed to make the requested and greatly needed reforms we will be today terminating our relationship with the World Health Organisation and redirecting those funds to other worldwide and deserving urgent global public health needs."

Trump reiterated his assertion that China covered up the virulence of the coronavirus that first emerged in Wuhan, a major city with international air transport links.

"China's cover up of the Wuhan virus allowed the disease to spread all over the world, instigating a global pandemic that has caused more than 100,000 American lives, and over a million lives worldwide," he said. "Chinese officials ignored their reporting obligations to the World Health Organisation and pressured the World Health Organisation to mislead the world."

"Why is it that China shut off infected people from Wuhan to all other parts of China?" he added. "It didn't go to Beijing ... but they allowed [people in Wuhan] to freely travel throughout the world, including Europe and the United States.

"The death and destruction caused by this is incalculable."

The WHO receives about 20 per cent of its funding from "assessed contributions" from individual UN member nations based on their gross domestic product and population, with the rest from voluntary contributions.

The US is the largest contributor, contributing about 15 per cent of the combined total " US$893 million last year, according to the WHO's own figures " followed by Britain and the Bill & Melinda Gates Foundation.

In the 2018-19 financial period, the WHO's target was to raise US$44.4 billion in funding. Of that, China contributed about US$76 million in assessed contributions and just over US$10 million in voluntary contributions.

This article originally appeared in the South China Morning Post (SCMP), the most authoritative voice reporting on China and Asia for more than a century. For more SCMP stories, please explore the SCMP app or visit the SCMP's Facebook and Twitter pages. Copyright © 2020 South China Morning Post Publishers Ltd. All rights reserved.

Copyright (c) 2020. South China Morning Post Publishers Ltd. All rights reserved.