President Donald Trump is attacking Joe Biden for calling on governors to mandate that all Americans wear masks for the next three months, accusing the Democratic presidential candidate of politicizing an issue Trump himself has used for political gain in recent months.

Trump claimed Biden has been wrong about the coronavirus pandemic at every turn, “ignoring the scientific evidence and putting left-wing politics before facts and evidence."

Trump went on to falsely say that Biden was advocating for the president to use executive power to institute a nationwide mask mandate and that Biden was in favor of “locking all Americans in their basements for months on end.”

“To Joe, I would say stop playing politics with the virus," the Republican president said at a White House press briefing.

Biden did not call for an executive order, but he did at an earlier campaign event call for the institution of "a mask mandate nationwide, starting immediately.” Biden clarified, however, that it should be left up to the governors to make mask-wearing mandatory.

He said nothing about keeping Americans indoors, but he has argued that economic reopenings in states have been rushed and without proper guidance from the federal government to keep Americans safe.

Trump spent the early months of the pandemic refusing to wear a mask during public appearances, ridiculing reporters who wore them and retweeting messages making fun of Biden for wearing a mask and implying that he looked weak. Trump first wore a mask in public about a month ago, during a visit to a military hospital, and he has since expressed support for them at times.

On Thursday, he said it's patriotic for Americans to wear masks, but he added, “maybe they're great, and maybe they're just good. Maybe they're not so good.”

Biden, at his earlier event, said all Americans should wear masks, citing health experts’ predictions that it could save 40,000 lives from the coronavirus over the next three months. The Democratic presidential candidate also responded to those who push back against such mandates.

“This is America. Be a patriot," he said. "Protect your fellow citizens. Step up. Do the right thing.”

The back-and-forth marked a new line of attack from Trump, who is trailing Biden significantly in most nationwide and swing state surveys. Biden has made what he says is Trump's mishandling of the pandemic — which has now caused the deaths of at least 167,000 people in the United States — a centerpiece of his attacks on the president.

While Trump has charged that if Biden were elected he would cause everything from a stock market crash to a surge of crime in the suburbs, he has largely avoided taking Biden on when it comes to the pandemic, choosing instead to deflect blame for the deaths and economic damage.

On Wednesday, when the U.S. reported 1,499 new coronavirus deaths, the highest number in a day since May, Trump pushed for schools and businesses to continue opening and called for college football to go on despite several leading leagues deciding to cancel this year’s season.

On Thursday, he again dismissed critics who say he was too slow to react to the pandemic in the U.S., claiming on Fox Business Network that “nobody blames me.”

“Look, we got hit by the China plague, and we’re not going to forget it," he said, “We got hit by the China plague.”