UN agencies reacted on Tuesday to US President Donald Trump's executive orders to end US membership in the World Health Organization (WHO) and the Paris Climate Agreement, highlighting the huge potential negative impact on public health and efforts to curb global warming.

“WHO regrets the announcement that the United States intends to withdraw from the Organization...We hope that the United States will reconsider its decision,” WHO spokesman Tarik Jasarevic said hours after the new U.S. president signed an executive order at the White House that will end U.S. participation in the U.N. agency in 12 months.

Asked about the impact of the US withdrawal, Jasarevic said he had read the executive order “this morning like everyone else” and that further analysis would be required.

He reiterated that the U.S. is WHO's largest donor, accounting for 18 percent of the agency's budget in 2023.

Responding to questions from reporters in Geneva, Jasarevic emphasized that WHO “plays a critical role in protecting the health and safety of people around the world, including Americans, by addressing the root causes of disease, building stronger health systems, and identifying, preventing and responding to health emergencies, including disease outbreaks, often in dangerous places where others cannot reach.”

The U.S. joined the WHO in 1948 after both houses of Congress passed a joint resolution, according to the UN press office. The resolution requires a country to give WHO one year's notice of its withdrawal from the organization.

 U.S. President Donald Trump took steps to withdraw from the WHO in 2020 during his first term as president, but the Joe Biden administration reversed the move.