The World Health Organization responded Tuesday to President Donald Trump's decision to withdraw the U.S. from the U.N. health organization, but didn't address any of the president's concerns.

Trump signed an executive order Monday to withdraw from WHO, a process that will take a year. In the order, Trump roundly criticized the agency for its handling of COVID-19 and how much member countries pay to participate, specifically noting that the U.S. contributes $500 million compared to China's $39 million.

WHO, based in Geneva, Switzerland, serves as the United Nation's health agency and is responsible global public health. WHO said it "regrets" Trump's executive order and defended its work.

"WHO plays a crucial role in protecting the health and security of the world's people, including Americans, by addressing the root causes of disease, building stronger health systems, and detecting, preventing and responding to health emergencies, including disease outbreaks, often in dangerous places where others cannot go," the organization said.

WHO also touted its accomplishments, highlighting U.S. contributions to WHO's work around the globe.

"For over seven decades, WHO and the USA have saved countless lives and protected Americans and all people from health threats," WHO said in a statement. "Together, we ended smallpox, and together we have brought polio to the brink of eradication. American institutions have contributed to and benefited from membership of WHO."

WHO also pointed to recent changes, but didn't directly address Trump's criticisms.

"With the participation of the United States and other Member States, WHO has over the past 7 years implemented the largest set of reforms in its history, to transform our accountability, cost-effectiveness, and impact in countries," it said. "We hope the United States will reconsider and we look forward to engaging in constructive dialogue to maintain the partnership between the USA and WHO, for the benefit of the health and well-being of millions of people around the globe."

In his order, Trump said he notified the UN about the proposed withdrawal in 2020 "due to the organization's mishandling of the COVID-19 pandemic that arose out of Wuhan, China, and other global health crises, its failure to adopt urgently needed reforms, and its inability to demonstrate independence from the inappropriate political influence of WHO member states."

"In addition, the WHO continues to demand unfairly onerous payments from the United States, far out of proportion with other countries' assessed payments," according to Trump's proclamation. "China, with a population of 1.4 billion, has 300% of the population of the United States, yet contributes nearly 90% less to the WHO."

Trump said that the U.S. had long been forced to overpay for WHO during a Monday evening news conference.

"We were paying $500 million. It seemed a little unfair to me," he said. "China pays $39 million and we pay $500 million and China's a bigger country."

The U.S. has been a part of WHO since 1948, the year the organization was founded. The U.S. withdrawal makes it the only major world power to exit the 194-country health organization.