Speaking to reporters on Tuesday, Ronny Jackson raised questions about Joe Biden's cognitive ability to be America's president. The former White House physician said he was convinced the Democratic presidential nominee isn't fit to be commander-in-chief.

Jackson cited what he described as cognitive decline to support his claim about Biden's mental unfitness for office. The remarks from the White House physician-turned-GOP congressional candidate, who has not evaluated the former vice president, came during a phone call arranged by Trump's campaign, and are an important part of an effort by Trump's allies to highlight Biden's mistakes on the campaign trail, claiming these gaffes make him mentally unfit for serving as commander in chief.

Jackson said that he remarked as a concerned citizen, rather than a Republican congressional candidate. He told reporters that as an American when he watches Biden on the campaign trail, he is concerned that the former veep lacks mental capacity and the cognitive ability to serve as the head of state and the country's commander in chief.

He went on to suggest that Biden needs some cognitive testing before taking over the reins of the country's commander in chief if he wins the election. Responding to a reporter's question, Jackson admitted that he has never treated or evaluated Biden but explained that he wasn't making a medical assessment of Biden's mental health, The Hill reported.

Claiming that he is not making a medical assessment, Jackson noted that he doesn't even practice medicine at the moment. He added that he wasn't trying to diagnose Biden with anything remotely, nor has he accused him of having Alzheimer’s or anything of that nature. "I have not made that statement,” he explained.

Backing his statement, Jackson recalled a few instances from earlier this week when Biden, who was in Ohio for a campaign rally, forgot the name of Sen. Mitt Romney (R-Utah), and mistakenly said he was running for the Senate, rather than the White House. Biden spokesman Andrew Bates responded to Jackson's comment in a statement that referred the former White House physician to the first debate.

While Trump and his campaign have been targeting Biden's mental fitness for a long time, the former vice president has garnered a considerable lead in national and an advantage in key battleground states during the same time. On the other hand, Trump has little time to revive his campaign, raising concerns among Republicans about potentially losing the Senate and the White House.