The former White House doctor for former President Barack Obama and retired Navy Rear Adm. Ronny Jackson said on Tuesday that Democratic presidential candidate Joe Biden is unfit for the presidency and should take a cognitive test before ever assuming the role.

On a media call with reporters, Jackson said he is convinced Biden “does not have the mental capacity” to be commander in chief, adding that Biden “needs some kind of cognitive testing” before he takes over the role.“He is not up for the job,” Jackson said.

“This is not the same Joe Biden we’ve known over the last 47 years,” Jackson said, pointing to recent gaffes Biden has made, such as forgetting or mixing up names, losing his train of thought, and incorrectly identifying the very political race in which he’s running.

Jackson served as White House physician for the Obama and Trump administrations from 2013 to 2018. He is now a Republican candidate for Texas’ 13th District in the U.S. House of Representatives.

“This is serious. We’re picking a commander-in-chief that has to be at the top of their game cognitively. And he’s really not,” Jackson added.

Jackson caveated his remarks on Biden’s cognitive abilities by saying he was not making a medical assessment, but rather a citizen observation.

“[Biden] wasn’t my patient, and I never had anything to do with his healthcare. … I’m saying it as a concerned citizen,” Jackson said, adding that he has experience with cognitive impairment and how those issues begin.

“Something is going on here. He’s having really bad days about where he is,” Jackson said. “He’s having a really extreme time focusing on the one task at hand when he gets up in front of voters and tries to explain something.”

President Donald Trump had repeatedly targeted Biden’s mental abilities in campaign ads and speeches.

One video, in particular, titled, “What Happened to Joe Biden?” showcases clips comparing Biden speaking during 2015 and 2016 to the 2020 presidential campaign. The earlier clips feature a more energetic Biden, while the latter shows Biden losing his train of thought.

In June, Trump said during an interview with Fox News, “Joe’s not all there. Everybody knows it, and it’s sad when you look at it and you see it.”

We’ve reached out to the Biden Campaign and the DNC for comment and both have refused.