Medical aid shipment from the World Health Organization (WHO) and the UN refugee agency, United Nations High Commissioner for Refugees (UNHCR), arrives at the Beirut-Rafic Hariri International Airport, in Beirut, Lebanon, 4 October 2024; Credit: Reuters/Louisa Gouliamaki/File Photo

UNITED NATIONS (Reuters) - The United States will leave the World Health Organization (WHO) on 22 January 2026, the United Nations said on Thursday 24 January 2025, after being formally notified of the decision by President Donald Trump, who has accused the agency of mishandling the pandemic and other international health crises.

Trump announced the move on Monday 20 January 2025, hours after he was sworn in for a second four-year term. The WHO said on Tuesday 21 January 2025 that it regretted the move from its top donor country.

Trump must give a one-year notice of US withdrawal from the Geneva-based body and pay Washington's dues under a 1948 joint resolution of the US Congress.

The United States is by far the WHO's biggest financial backer, contributing around 18% of its overall funding. WHO's most recent two-year budget, for 2024-2025, was $6.8 billion. It was not immediately clear how much the US owes.

"I can confirm we have now received the US letter on the WHO withdrawal. It is dated 22 January 2025. It would take effect a year from yesterday, on 22 January 2026," said deputy UN spokesperson Farhan Haq.

The US departure will likely put at risk programmes across the organisation, according to several experts inside and outside the WHO, notably those tackling tuberculosis, the world’s biggest infectious disease killer, as well as HIV/AIDS and other health emergencies.

The withdrawal order signed by Trump said the administration would cease negotiations on the WHO pandemic treaty while the withdrawal is in progress. US government personnel working with the WHO will be recalled and reassigned, and the government will look for partners to take over necessary WHO activities, according to the order.

Trump's withdrawal from the WHO was not unexpected. He took steps to quit the body in 2020 during his first term as president. Before the US withdrawal could be completed last time, Joe Biden won the presidential election and put a stop to it on his first day in office on 20 January 2021.