More than 100 former U.S. officials in health and national security warned that ending U.S. funding for the Pan American Health Organization (PAHO) could increase vulnerability to infectious diseases domestically and across the Americas. The warning came in an open letter released Thursday, amid the Trump administration’s plan to eliminate U.S. contributions to the regional health agency.

PAHO, established in 1902, coordinates public health initiatives across 35 member countries, including the United States, which is a founding member. The U.S. currently owes nearly $135 million in overdue fees to the organization dating back to late 2024. The Trump administration formally withdrew the United States from the World Health Organization (WHO) on its first day in office and proposed eliminating next year’s funding for PAHO, which acts as WHO’s regional arm in the Americas.

The former officials, including health secretaries, agency directors, Pentagon and White House aides, and surgeons general with experience in both Republican and Democratic administrations, argued that cutting support undermines critical disease detection and response mechanisms. They cited growing threats from infectious diseases like dengue, avian influenza, and screwworm. “A nation that cannot detect and contain disease threats at their source cannot fully protect its people at home,” the letter said.

PAHO has been credited with helping the Americas become the first region worldwide to eliminate polio and other diseases, as well as aiding the eradication of smallpox. The agency also provides emergency support, such as during Venezuela’s June earthquakes, and facilitates access to treatments for illnesses like cancer and HIV. During the 2023 World Cup, PAHO coordinated daily meetings between the United States, Canada, and Mexico to prepare for potential health risks from increased tourism, according to Dr. Jarbas Barbosa, PAHO’s director.

Brazil’s Health Minister, Dr. Alexandre Padilha, criticized the U.S. stance, calling it a “denialist” approach that jeopardizes regional health security. He emphasized that weakening multilateral institutions like WHO and PAHO harms global health and the United States itself.

The United States currently covers roughly 20 percent of PAHO’s budget, despite this amount representing only about 0.001 percent of overall U.S. federal spending. While Spain and other observing members have contributed additional funds, PAHO officials say these donations have not compensated for the U.S. shortfall. Dr. Barbosa stated he has repeatedly requested payment from the U.S. government but has received no formal response.

Public health experts underscored the importance of PAHO’s collaborative networks, including laboratories that analyze pathogen genetics to track the spread of emerging diseases throughout the hemisphere. Disruption of these efforts could hinder timely identification and response to threats entering the United States through food or animal vectors.

PAHO has also been involved in assessing whether the U.S. has lost its measles elimination status in 2023, as the country has recorded its highest number of cases since eliminating the disease in 2000. Dr. Barbosa noted that he did not believe the organization’s role in this process influenced the funding decision.

While supporting efforts to reform and increase accountability in international organizations, Dr. Barbosa highlighted PAHO’s recent 19 percent budget reduction through staff cuts, decentralization, and reduced travel since his appointment as director in 2023. He said PAHO now publishes audit reports for all member countries to enhance transparency. “The general concerns they have shared about international organizations — we are already implementing them,” he said.

The U.S. Office of Management and Budget did not respond to a request for comment. A State Department spokesperson reiterated the administration’s commitment to protecting American taxpayers by pushing reforms to ensure U.S. funds are not used in ways contrary to national interests.