President Trump announced Tuesday, at yet another contentious White House briefing, that the U.S. would suspend funding to the World Health Organization, citing the group’s role in “severely mismanaging and covering up the spread of the coronavirus.”

While his supporters backed the move, Microsoft MSFT, -1.24% co-founder Bill Gates clearly didn’t, and he let his feelings be known on Twitter TWTR, +2.03% :

“Halting funding for the World Health Organization during a world health crisis is as dangerous as it sounds,” the billionaire wrote. “Their work is slowing the spread of COVID-19 and if that work is stopped no other organization can replace them. The world needs @WHO now more than ever.”

The Bill and Melinda Gates Foundation has pledged up to $100 million to help contain the coronavirus just a week after the WHO declared the outbreak a global public health emergency at the end of January. The outbreak was declared a pandemic on March 11. A chunk of the foundation’s donation went to both the WHO and the Centers for Disease Control and Prevention.

Gates has been vocal in recent weeks about the need for stricter social-distancing measures. Late in March, he made his case in an op-ed for the Washington Post.

“Despite urging from public health experts, some states and counties haven’t shut down completely,” he said. “In some states, beaches are still open; in others, restaurants still serve sit-down meals. This is a recipe for disaster. Because people can travel freely across state lines, so can the virus.”

As for the WHO, Trump blamed the group for failing to get experts in China to objectively assess the situation on the ground and to call out the country’s lack of transparency. “The outbreak could have been contained at its source with very little death,” he said at the briefing.

Last week, the WHO director-general responded to prior critiques from the president.

“If you don’t want many more body bags, then you refrain from politicizing it,” Tedros Adhanom Ghebreyesus said in a statement. My short message is: Please quarantine politicizing COVID. The unity of your country will be very important to defeat this dangerous virus.”

Gates isn’t the only one airing concerns over the president’s move to pull the financing.

“During the worst public health crisis in a century, halting funding to the World Health Organization is a dangerous step in the wrong direction that will not make defeating COVID-19 easier,” American Medical Association President Patrice Harris said in a statement cited by CNN.