One year after President Donald Trump signed an executive order ending US membership in the World Health Organization (WHO), the decision is now set to take full effect on Thursday.
The rules governing US participation in the Geneva-based UN health agency require a formal 12-month notice period before withdrawal can be finalized. That waiting period concludes this week, making the exit official.
Although the departure is proceeding, not all contractual obligations were met. The United States failed to pay its full assessed contributions before leaving. Despite this shortfall, the WHO lacks any authority to collect the unpaid funds or prevent the withdrawal from moving forward.
WHO Director-General Tedros Adhanom Ghebreyesus has publicly appealed for the United States to reconsider. Speaking from Geneva, he warned that the decision weakens both the US and global public health efforts, emphasizing that collaboration—not finances—is at the heart of the organization’s mission.
The WHO is responsible for monitoring potential disease threats worldwide, including systems designed to detect emerging outbreaks. It also oversees the global process used to determine the composition of seasonal influenza vaccines by reviewing data on circulating viruses. With the US no longer involved, these programs will continue without American participation or expertise.
Tensions between Trump and the WHO first escalated during the COVID-19 crisis. During his initial presidency, Trump moved to withdraw the country from the organization, citing dissatisfaction with its response to the pandemic. That effort was halted when President Joe Biden assumed office before the withdrawal became official and restored US membership.
After returning to the White House, Trump revived his criticism of the WHO, accusing it of poor leadership and financial mismanagement. His administration subsequently declined to pay outstanding dues for 2024 and 2025, leaving an estimated $280 million unpaid.
Historically, the United States was the organization’s largest financial supporter. Beyond mandatory membership fees, it regularly provided voluntary funding, often contributing more than 15 percent of the WHO’s total annual budget.
The sudden loss of US funding has forced the WHO to implement sweeping budget reductions. By mid-2026, staffing levels are expected to fall by roughly one-fifth, leaving an estimated workforce of about 7,300 employees compared with early 2025. Overall spending is projected to decline at a similar rate.
