President Donald Trump during his White House press briefing On Thursday attacked presumptive Democratic nominee Joe Biden for his national mask mandate proposal, accusing him of politicizing the pandemic and calling Biden “anti-scientific” and “defeatist.”

Experts have said that a national mask mandate could save up to 40,000 Americans this year alone if implemented.

“It’s a shameful situation for anybody to try and score political points while we’re working to save lives and defeat the pandemic,” Trump said at the press briefing.

Trump’s comments come after Biden called in for national mask mandate during a brief appearance before reporters in Wilmington, Delaware on Wednesday. He said that “every single American should be wearing a mask when they’re outside for the next three months at a minimum.” Biden urged the governors of every U.S. state to “mandate mandatory mask wearing,” adding that medical experts think this measure “will save 40,000 lives in the next  three  months.”

Trump claimed Biden in his announcement was spreading “left-wing politics” and “ignoring scientific evidence.”

Trump, while encouraging Americans to wear masks and calling it “patriotic,” did not support mandating a rule, saying he wanted Americans to have “certain freedom.”

“We have urged Americans to wear masks. We’ve been saying wear them when it’s appropriate,” Trump said. “Maybe they’re great and maybe they’re just good, maybe they’re not so good. But frankly what do you have to lose? You have nothing to lose.”

Trump also accused Biden of trying to “lock all-Americans in their basements for months on end” and claimed Biden wanted to “shut down our economy.”

“He wants to shut down our economy, close our schools, and grind society to a halt and he wants it done by a federal decree. This would lead to a crippling, long-lasting depression,” Trump said. “We’ll defeat this virus, but not by hiding in our basements, he’s got to come out of his basement. We’ll defeat this virus through a common sense mitigation effort, shielding those at highest risk and unleashing America’s medical and scientific genius.”