The United States formally left the World Health Organization on 23 January 2026. The exit follows an executive order President Donald Trump signed at the start of his second term. The US still owes about US$260 million in dues, has stopped all funding and has withdrawn its staff. It was the WHO's largest donor, giving nearly US$1.3 billion in 2022-23. A 1948 US law requires a year's notice and payment of dues before leaving.