(NewsNation) — A former White House physician believes all presidential candidates should undergo a “comprehensive neurocognitive assessment,” he told “The Hill on NewsNation.”

Dr. Jeffrey Kuhlman worked with former Presidents Bill Clinton, George W. Bush and Barack Obama during his 13-year tenure in the White House. Those leaders all served during their 50s, a two-decade difference from this election season’s first round of front-runners.

Kuhlman’s recently published New York Times op-ed asking for increased assessments comes in the wake of mounting concerns over President Joe Biden and former President Donald Trump‘s advanced ages.

The criticisms and internal calls grew so loud that Biden dropped his 2024 White House bid on Sunday, endorsing his younger counterpart, Vice President Kamala Harris, instead.

Kuhlman did not explicitly say whether the White House handled the concern over Biden’s health appropriately, only emphasizing that a White House physician has the duty to serve the president and remain candid with the nation.

He did clarify that while the current policy is to assess cognitive issues as they appear, he believes an annual evaluation would best serve the American people.

“What I would propose is, at age 70, maybe every year you do a four-hour neurocognitive assessment if you’re the president or the vice president or you’re seeking that office. … You have to have that baseline,” Kuhlman said.

In the Times piece, Kuhlman also advocated for imposing an age limit on the nation’s highest office, citing “the realities of cognitive decline with aging.”

“The federal Age Discrimination in Employment Act forbids mandatory retirement before age 70 for many jobs, but it does allow exceptions for public safety, such as for F.B.I. agents and airline pilots,” his article reads. “Given the physical and mental rigors of the presidency, shouldn’t we have an age limit as well on this position — the ultimate public safety position?”