The Gates Foundation said on Tuesday it will commit $1.6 billion over the next five years to support Gavi, a public-private partnership that helps buy vaccines for the world’s poorest children.

The number of kids dying around the world will likely go up this year because of the massive cuts to foreign aid, foundation chair Bill Gates said in a statement, adding that funding Gavi was the single most powerful step to stop it.

“The legacy of our generation cannot be that we looked away as millions of poor children died of preventable causes,” said Gates.

“The world now has affordable, effective, proven tools that save lives. Wealthy nations should fully fund Gavi and the Global Fund, the organisations created to get those products to the people who need them.”

The vaccine alliance is looking to raise $9bn for its work from 2026 to 2030 at a pledging event to be held in Brussels on Wednesday. It is co-hosted by the European Union and the Gates Foundation.

The Trump administration had previously indicated that it planned to cut its funding for Gavi, representing around $300 million annually.

Losing US funding could lead to around 1.2m additional deaths over the next five years, Gavi CEO Sania Nishtar had said.

The alliance works along with governments to fund the purchase of vaccines to prevent deadly diseases such as measles and diphtheria.