On his first day in office, President Trump signed an executive order aimed at withdrawing the U.S. from the WHO. He cited several reasons for the decision, including the organization's "mismanagement" of the COVID-19 pandemic and its "failure to implement necessary reforms." Trump also criticized the financial contributions required from the U.S., claiming that they were disproportionate compared to China’s contributions.

The move was not surprising, as Trump had been vocal in his criticism of the WHO since 2020, accusing the agency of mishandling the pandemic and threatening to cut off U.S. funding. In July 2020, he took formal steps to initiate withdrawal. However, after losing the 2020 election, the planned withdrawal was blocked by President Joe Biden on his first day in office, January 20, 2021.

If the U.S. were to leave the WHO, it would lose access to crucial global health data, including the genetic sequence of the coronavirus, which China initially shared with the WHO, enabling other nations to track the virus’s spread. Additionally, the WHO has been a target of conservative criticism, especially regarding its involvement in discussions about a "pandemic treaty" aimed at strengthening global pandemic preparedness. 

The treaty, which sought to create legally binding policies on pathogen surveillance, data sharing, and vaccine production, faced opposition from some U.S. lawmakers who saw it as a threat to American sovereignty. Negotiations on the treaty collapsed last year.

Lawrence O. Gostin, a public health law expert at Georgetown University who contributed to the treaty's negotiation, argued that a U.S. departure from the WHO would be a "grievous wound" to global health and a serious blow to U.S. national security.

Founded in 1948 with significant U.S. support, the WHO is a specialized agency of the United Nations that addresses global health challenges. Its mission includes providing aid in conflict zones like Gaza and monitoring emerging diseases such as Zika, Ebola, and COVID-19. The WHO's budget is approximately $6.8 billion, with the United States historically contributing a large portion.

Gostin noted that the U.S. withdrawal process would take time, as U.S. law requires a year’s notice and the payment of financial obligations for the current fiscal year before withdrawal can be completed.