Elon Musk, the richest person in the world, says he will sell $6 billion worth of Tesla stock and donate the proceeds to the United Nations’ food agency if it could show how the money would solve world hunger.

His statement came after U.N. World Food Programme Executive Director David Beasley challenged Musk, Amazon founder Jeff Bezos and other billionaires in a CNN interview last week, calling on them to step up on “a one-time basis” to help end starvation.

In the interview, Beasley said billionaires could give “$6 billion to help 42 million people that are literally going to die if we don’t reach them.”

“It’s not complicated,” he said.

That money would be approximately 2% of Musk’s fortune, nearly $300 billion, according to Forbes. His wealth and the wealth of many American multi-billionaires has grown quickly during the COVID-19 pandemic, thanks to increased stock and home equity, even more than before the virus struck.

The SpaceX founder posted Sunday on Twitter: “If WFP can describe on this Twitter thread exactly how $6B will solve world hunger, I will sell Tesla stock right now and do it.”

“But it must be open source accounting, so the public sees precisely how the money is spent,” he added.

In 2020, the agency received $8.4 billion in donations, which it says was $5.3 billion short of its requirements. Its top donors include the United States, Germany and the United Kingdom.

Beasley responded to Musk on Twitter, writing $6 billion will not solve world hunger, “but it WILL prevent geopolitical instability, mass migration and save 42 million people on the brink of starvation. An unprecedented crisis and a perfect storm due to Covid/conflict/climate crises.”

He also offered to meet with Musk to discuss the topic.

“Please publish your current & proposed spending in detail so people can see exactly where money goes,” Musk said in a Twitter reply. “Sunlight is a wonderful thing.”

It remained unclear Monday whether a meeting will be set.