Kamala Harris is once again pressing her Republican opponent on whether he’s fit for office, citing a report that an “exhausted” Donald Trump is canceling public appearances.

“I’ve been hearing reports that his team, at least, is saying he’s suffering from exhaustion,” the vice president told reporters on Friday, citing Trump’s refusal to participate in another debate and other canceled events, which Politico reported was due to exhaustion, citing an anonymous Trump adviser.

“Being president of the United States is probably one of the hardest jobs in the world, and so we really do need to ask: If he’s exhausted being on the campaign trail, is he fit to do the job?” she said.

MSNBC and NBC News have not verified Politico’s report, but Trump, who is 78, has indeed bailed on several media interviews and event appearances in recent weeks, often citing “scheduling conflicts.” He has, however, largely honored commitments with friendly conservative outlets, where he receives little pushback. (On Friday morning on “Fox & Friends,” for example, he suggested that if Harris is elected, “you will have no more cows,” echoing his 2019 lie about the Green New Deal.) One of his recent campaign appearances also took a strange turn, when he stopped taking questions during a Monday town hall and instead bopped to music onstage for nearly 40 minutes. And at a Michigan rally on Friday night, he ambled aimlessly around the stage for 20 minutes after his microphone cut out.

In the final stretch of the election, Harris has tried to hammer home the narrative that Trump is not physically and temperamentally fit enough for office. She has increasingly brought up that line of attack against him on the campaign trail, and her campaign this week released an ad warning that his second term would be “more unhinged, more unstable and unchecked.” Her campaign also released her medical records last week, drawing attention to Trump’s refusal to do so. (Trump told CBS News in August that he would make his health records public, but to date he has only released a one-page letter from a physician, Rep. Ronny Jackson, R-Texas, describing the gunshot wound Trump sustained during the July assassination attempt.)

Trump having to answer for his mental and physical fitness for office is a stark shift from earlier in the election when he repeatedly attacked his then-opponent, President Joe Biden, over concerns about the president’s age and cognitive ability. Trump’s own mental state has been increasingly called into question in the last few weeks, as his characteristic ramblings have grown harder to parse and his behavior more erratic than usual.