Rep. Ronny Jackson, R-texas, says the apparent cognitive decline of President Joe Biden puts the country at “great risk right now.”

Jackson, who served as a physician in the White House under Presidents George W. Bush, Barack Obama, and Donald Trump, expressed concern that Biden’s cognitive ability has worsened since his presidential term began in 2021.

“I know firsthand what it takes to be the commander in chief and the head of state. It’s a grueling job, both mentally and physically. This man can’t do the job. He’s proven to us every single day that he can’t do the job, but this is going to get worse,” Jackson said on Fox News’s Sunday Morning Futures.

“I’ve been saying this since he was candidate Joe Biden. And like you said, I wasn’t making a diagnosis, but I said this man’s got cognitive issues related to his age. It just continues to get worse,” he added.

Jackson also said that electing Biden to a second term in 2024 is something the country “cannot afford to have,” emphasizing how much he believes the president’s cognitive ability has visibly declined in the past three years.

“I went back and looked at stuff from two or three years ago — over three years ago when he was running for office — and compared it to right now. It’s just unbelievable how much he’s degenerated just during his time in office. We cannot afford to have this man in office for the remainder of this term and then another four years after that. He’s already putting us at great risk right now,” Jackson said.

Biden, 81, is the oldest president in United States history and would be 86 upon leaving office if elected to a second term in 2024.