National security expert sounds alarm over Biden’s health: 'Can't have a part-time commander-in-chief'

Former Trump national security official Gen. Keith Kellogg (Ret.) sounded the alarm about President Biden's fitness for a second term, warning that the U.S. cannot have a "part-time commander-in-chief" as Biden prepares to address NATO leaders. 

"Let's go back to the Federalist Papers, back when we were forming the Constitution, and Alexander Hamilton was asked a question, and he wrote in the Federalist Papers, ‘What is one of the key attributes of a... national leader?’ And he said, energy, and he was talking both intellectual energy and physical energy," the former Army lieutenant general told Steve Doocy during "Fox & Friends" on Tuesday. 

"So you even go back to the start of our republic and what was essential for a commander-in-chief. You can't have a part-time commander-in-chief."

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The former national security adviser to VP Mike Pence noted the importance of making split-second decisions at any hour, a capability called into question by both Democrats and Republicans alike after the president's debate performance. 

"I cannot tell you how many times we had to wake… President Trump up, in the middle of the night, to have a decision, and he was right on it right away," he said. "Look, that time when we killed Soleimani, we woke him up in the middle of the night. We got an answer that was on the 1st of January 2020. On the 3rd of January 2020, Soleimani was dead. That was a quick decision, a hard decision made in the middle of the night. So that's the kind of attribute you want as a commander-in-chief."

"And that's what the world wants to have, and that's what these leaders were coming together today, and the NATO summit wants to see as well," he continued. "There's a real question that they have got, and the world has got, ‘Can this guy, President Biden, actually do the job? Other than just 5 or 6 hours a day?’"

Axios reported that the president has struggled to operate outside of a 10 AM to 4 PM workday window, or after international travel.

Biden appeared to freeze while on the debate stage facing off against former President Trump. He also stumbled over his words, mumbled and wrestled with conveying complete thoughts at times. 

His performance has brought into question his ability to lead the country through a second term, from both Democrats and Republicans.

Meanwhile, Biden will address NATO leaders at the 75th anniversary summit in Washington, D.C. on Tuesday night. 

His remarks are slated to come after NATO Secretary General Jens Stoltenberg appeared to dodge questions about President Biden's mental fitness to lead the alliance on a tumultuous world stage. He told Fox News on Sunday he refuses to become a part of domestic U.S. debate.

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"What I can say is that I just had, a couple of weeks ago, a good and productive meeting with President Biden in the Oval Office, and that we, this week, will make important decisions at the NATO summit in Washington on deterrence, defense, on Ukraine, and also to work more closely with our Asia-Pacific partners to address the threats and challenges posed by China," he told Fox News' Joey Jones.

He continued: "Of course, all these decisions that will take place this week would not have been possible without U.S. leadership, so I look forward to an important summit in Washington this week."

Despite growing, bipartisan calls for Biden to step aside ahead of the November election, the president has vowed to stay in the race even with dismal support. 

"The bottom line here is that we’re not going anywhere. I am not going anywhere," Biden told MSNBC hosts Mika Brzezinski and Joe Scarborough, both avid White House supporters, on Monday. 

"I wouldn’t be running if I didn’t absolutely believe that I am the best candidate to beat Donald Trump in 2024," he said. "We had a democratic nominating process where the voters spoke clearly. I won 14 million of those votes."

Fox News' Taylor Penley and Nikolas Lanum contributed to this report. 

Bailee Hill is an associate editor with Fox News Digital. Story ideas can be sent to This email address is being protected from spambots. You need JavaScript enabled to view it.