BEDMINSTER, New Jersey — Former President Donald Trump, the leading GOP candidate for president in 2024, says that while he “probably” expects to face incumbent Democrat President Joe Biden in a rematch next year, the sitting president’s apparent health issues are worse with regard to his “mental” problems than his “physical” problems.

“I can only say probably,” Trump said when asked if he expects to face Biden in November 2024 in a rematch in the general election. “I mean, I watch him walking out of a helicopter. I watch him—just watch him. He can’t walk up a flight. He hasn’t gone down going down a flight but going up a flight he seems to have a problem. He can’t go up a flight of stairs. I think he’ll—I don’t know. Physically and mentally, I think his mental is worse than his physical if you want to know the truth.”

Trump also said he is unsure if Biden “makes it” to the general election next year and again while he expects to “probably” face Biden he knows other Democrats who really want to run against him who are not currently doing so. No matter who he faces in November 2024 assuming he wins the GOP nomination, though, Trump said, “It’s all right” — he will be ready for them.

“As to whether or not he makes it, I have no idea,” Trump said. “Whoever it is, it’s all right. I don’t like to predict. I would say that there are some other people who would like it. I wouldn’t be surprised if somebody actually did give him a real challenge at some point.”

The fact that Trump is lighting up Biden on his health problems is a big development and noteworthy for a number of reasons. Earlier this year, Trump warned Fox News host Sean Hannity not to joke about Biden’s health issues and Trump—who is 77 now and would be 78 entering office if he retakes the White House—has generally avoided the topic.

But now, Trump ripping into Biden over the very serious health issues he and the nation have watched play out on television in recent months suggests Trump understands the public is uneasy about Biden’s physical health and mental acuity. Indeed, recent polling shows more than two-thirds of Americans are concerned—an NBC News poll earlier this summer found that 68 percent of Americans believe that Biden does not have the “necessary” physical and mental health to serve as president of the United States. A majority, 55 percent, say they have “major” concerns with Biden’s health. By comparison, that poll showed far less concern about Trump than Biden with 55 percent saying they are concerned and just 44 percent saying they have “major” concerns. Those totals suggest the Trump numbers fall mostly along partisan lines while the Biden numbers are broadly bipartisan, transcending typical political bickering.

What’s more, Biden’s health issues, both mental and physical, have intensified recently. Earlier this summer, Biden tripped on stage at the Air Force Academy, falling down in front of the nation watching but later brushing it off as a joke claiming he was “sandbagged.” He has frequently tripped up the stairs, as Trump mentioned, when boarding Air Force One—and even fell off his bike in Delaware in front of reporters. In mid-June, Biden also had a big gash visible above his eye per photos from a trip to Pennsylvania:

Biden often trails off mid-thought in speeches too, and frequently needs aides to guide him off stage. In a recent MSNBC interview with Nicolle Wallace, for instance, Biden wandered off the set on live television in a particularly awkward moment.

In addition to these physical and mental problems, long-term health issues keep piling up for Biden. White House officials have confirmed markings on his face are from sleeping with a CPAP machine for sleep apnea, and earlier this year the president had cancerous lesions removed from his chest.