Joe Biden said Tuesday that President Donald Trump was “an absolute fool” for mocking the presumptive Democratic nominee for wearing a mask on Memorial Day.

Biden told CNN that Trump refusing to wear a mask in public is setting a poor example as “every leading doc in the world is saying we should wear a mask when you’re in a crowd.”

“This macho stuff, for a guy — I shouldn’t get going, but it just, it costs people’s lives. It’s costing people’s lives,” Biden said, adding that “presidents are supposed to lead, not engage in folly and be falsely masculine.”

Memorial Day marked the first public appearance for Biden since the pandemic began, and Tuesday was his first interview. Both he and his wife, Jill Biden, wore black masks as they attended an event at the Delaware Memorial Bridge.

Fox News host Brit Hume tweeted a photo after the event of Biden donning the mask, which Trump later reshared.

“This might help explain why Trump doesn’t like to wear a mask in public,” Hume wrote, seemingly mocking the former Vice President’s appearance.

Biden’s comment comes as Trump’s continuous refusal to wear a mask in public against the recommendation of the Center for Disease Control has drawn criticism.

During a tour of a Ford factory in Michigan last week, Trump told reporters that he had worn a mask in the “back area” but “didn’t want to give the press the pleasure of seeing it.”

White House Press Secretary Kayleigh McEnany later criticized Biden for not wearing a mask when he is at home with his wife, despite federal guidelines not recommending that people in the same household wear masks when they are with each other.

“It is a bit peculiar, though, that in his basement, right next to his wife, he’s not wearing a mask. But he’s wearing one outdoors when he’s socially distant,” McEnany said Tuesday. “So I think that there was a discrepancy there.”