After two and a half decades of decline, child mortality rates attributable to preventable diseases are now projected to increase, marking the first such reversal in 25 years.

This new estimate originates from models developed by the Institute for Health Metrics and Evaluation at the University of Washington and was first unveiled in the from the Gates Foundation. It indicates that an additional 200,000 children under the age of five could die this year from illnesses that modern medicine can prevent, either through vaccines or other treatments. According to the report, these deaths are primarily linked to various economic and political factors, most notably significant reductions in global health spending by the world’s largest donors, including the U.S.

“It’s a tragedy that the world is richer, and yet because we have made disproportionate cuts to the money that helps the world’s poorest children, more of them are dying,” stated Bill Gates, chair of the Gates Foundation, in an interview with TIME.

Many of the foundation’s initiatives concentrate on enhancing the health of mothers and children worldwide to decrease childhood mortality. Gates previously that he plans to spend the foundation’s remaining funds over the next 20 years. One of his aspirations is to halve the childhood mortality rate by that time, reducing it from the current 4.8 million annual deaths of children under five to approximately 2.5 million. However, he observed, “you can’t cut something in half if it’s going up.”

Over the past year, the leading donors to global health have reduced their contributions by nearly 27%. The report estimates that if these cutbacks continue or even deepen to 30%, an additional 16 million or more children could die from preventable causes by 2045.

Reduced spending on global health initiates a detrimental cycle, Gates explained, that can perpetuate poverty in countries, particularly those in Africa, and prevent them from building and sustaining their own health systems. “Being generous now means kids in those countries are surviving and well-nourished enough to contribute to the countries’ economic growth,” he asserted. “Investments now will make that possible.”

However, Gates believes the increase in childhood mortality is likely to persist over the next few years, mainly due to the severity of the aid reductions. “There will very likely be no near-term reversal on aid generosity,” he commented, “so the risk is that [childhood mortality] will get a lot worse.”

While some wealthier nations are prioritizing other spending areas—including defense—Gates argues that a significant difference can be made with relatively modest contributions. “For rich countries, it is less than 1% of the budget,” he noted. He emphasized that the impact of ensuring pregnant mothers and children are vaccinated and fed “ is so great that you see very good health outcomes when you focus on those first few interventions alone.” Investing in primary care is highlighted as a key priority for optimizing scarce resources, as fundamental health services can prevent more serious and costly medical needs in the long term.

Despite the alarming reversal in childhood mortality rates, Gates remains optimistic that the trend will begin to move in the right direction again within a few years, thanks to forthcoming innovations such as new RSV vaccines and treatments for malaria and tuberculosis. AI-based programs, which can accelerate the development of new treatments and improve access to healthcare, are also expected to positively influence health outcomes like mortality. Given the severe shortage of doctors in Africa, where “most people will spend their entire lifetime never seeing a doctor—not when they are born, not when they die, and not in between,” Gates sees AI systems as a crucial tool to bridge this gap and connect people to quality care. The Gates Foundation is currently involved in pilot programs using AI to monitor and advise expectant mothers and individuals with HIV, helping them manage their conditions and guiding them on when to seek care.

Nevertheless, the speed at which these innovations reach people will depend on continued funding for global health, according to Gates, from both philanthropies like the foundation and governments. “It is money extremely well spent, so we need to get the generosity back,” Gates urged. “And I will do my best to work with the President and with Congress to do that.”