Speaking at the White House hours after his inauguration, Trump said the US was paying far more to the UN body compared to China, adding: “World Health ripped us off.”

The US, the largest donor to the Geneva-based organisation, provides substantial financial support that is vital to the WHO’s operations.

Its withdrawal is expected to trigger a significant restructuring of the institution and could further disrupt global health initiatives.

This marks the second time Trump has sought to sever ties with the WHO.

During his first term, the US issued a notice of intent to withdraw, accusing the organisation of being overly influenced by China during the pandemic’s early stages.

That move was later reversed under former president Joe Biden’s administration.

In his new executive order, Trump directed agencies to “pause the future transfer of any US government funds, support, or resources to the WHO” and to “identify credible and transparent US and international partners to assume necessary activities previously undertaken by the WHO.”

The administration also announced plans to review and rescind Biden’s 2024 US global health security strategy, which was designed to prevent, detect, and respond to infectious disease threats, “as soon as practicable”.

The timing of the US withdrawal comes amid mounting fears over the pandemic potential of the current bird flu outbreak (H5N1), which has infected dozens and claimed one life in the US.

Meanwhile, WHO member states have been negotiating the world’s first treaty on pandemic prevention, preparedness, and response since late 2021 – negotiations now set to proceed without US participation.