The US is due to officially exit the World Health Organisation on Thursday, in the face of warnings it will hit both US health and global health and also in violation of a US law that requires Washington to pay the UN health agency $260 million in fees that it owes.

President Donald Trump gave notice that the US would quit the organisation on the first day of his presidency in 2025.

Under US law, it has to give one-year notice and pay all outstanding fees before departure.

Over the last year, many global health experts have urged a rethink, including most recently WHO Director General Tedros Adhanom Ghebreyesus.

“I hope the US will reconsider and rejoin WHO,” he told reporters at a press conference earlier this month.

“Withdrawing from the WHO is a loss for the United States, and it’s a loss for the rest of the world.”

Quick return unlikely

The WHO also said that the US has not yet paid the fees it owes for 2024 and 2025.

Member states are set to discuss the US departure and how it will be handled at the WHO’s executive board in February, a WHO spokesperson told Reuters by email.

The US State Department did not respond to questions about whether the US could leave without paying its fees or what the departure may mean for global collaboration.

“This is a clear violation of US law,” said Lawrence Gostin, founding director of the O’Neill Institute for Global Health Law at Georgetown University in Washington, a close observer of the WHO.

“But Trump is highly likely to get away with it.”

Speaking to Reuters at Davos, Bill Gates – chair of the Gates Foundation, a major funder of global health initiatives and some of the WHO’s work – said he did not expect the US to reconsider in the short-term.

“I don’t think the US will be coming back to WHO in the near future,” he said, adding that when he had an opportunity to advocate for it, he would.

“The world needs the World Health Organisation.”

What does the departure means

For the WHO, the departure of the US has sparked a budgetary crisis that has seen it cut its management team in half and scale back work, cutting budgets across the agency.

Washington has traditionally been by far the UN health agency’s biggest financial backer, contributing around 18% of its overall funding.

The WHO will also shed around a quarter of its staff by the middle of this year.

The agency said it has been working with the US and sharing information in the last year.

It was unclear how the collaboration would work going forward.

Global health experts said this posed risks for the US, the WHO and the world.

“The US withdrawal from WHO could weaken the systems and collaborations the world relies on to detect, prevent, and respond to health threats,” said Kelly Henning, public health programme lead at Bloomberg Philanthropies, a US-based non-profit.