A public moment last month when President Biden appeared temporarily unable to say the name of Homeland Security Secretary Alejandro Mayorkas reportedly left allies alarmed and "shaken up."

The incident took place on June 18 at an event celebrating the anniversary of the 2012 Deferred Action for Childhood Arrivals program, which protected some illegal immigrants from deportation.

As he spoke, Biden introduced Mayorkas, who has served in a high-profile role since 2021 and has been the main official dealing with the ongoing crisis at the southern border.

BIDEN APPEARS TO FREEZE UP, FORGET HOMELAND SECURITY SEC'S NAME DURING WHITE HOUSE EVENT: ‘ALL KIDDING ASIDE’

"Thanks to all the members of the Congress and Homeland Security Secretary," he said, pausing. "I…I’m not sure I’m going to introduce you all the way." 

He then added, "But all kidding aside, Secretary Mayorkas."

BIDEN BLAMES EUROPEAN TRIPS FOR DEBATE FLOP, DESPITE LONG HUDDLE AT CAMP DAVID: ‘ALMOST FELL ASLEEP ONSTAGE’

The New York Times reported this week that two people with a clear view of Biden, who has fought a stutter throughout his life, said that his soft-spoken mumbling and fumbling over words left some concerned.

The Times reported that President Biden's tone and the struggle to name Mayorkas led to allies trading "alarmed looks" and later describing themselves as "shaken up." However, another person said they hoped it was a "one-off" bad moment for Biden.

The report comes amid broader concerns about Biden’s mental acuity that have been bubbling for years, but they boiled over at last week’s presidential debate, where Biden was widely seen to have performed poorly.

It has sparked calls from some Democrats and some liberal media outlets that the president should drop out of the 2024 election. 

The Times’ Editorial Board penned an op-ed last week titled "To Serve His Country, President Biden Should Leave the Race."

However, the White House and the Biden campaign have repeatedly dismissed those questions about his health.

BIDEN TRIES TO FLIP THE SCRIPT ON NEGATIVE NARRATIVE COMING OUT OF DISASTROUS DEBATE WITH TRUMP

"Does President Biden, at 81 years old, have Alzheimer's, any form of dementia or degenerative illness that cause these sorts of lapses? And it's a yes or no question," a reporter asked White House press secretary Karine Jean-Pierre on Tuesday afternoon.

"Are you ready for it? It's a no. And I hope you're asking the other guy the same exact question," Jean-Pierre responded, referring to former President Trump.

Biden himself addressed his poor debate performance last week at a rally in Raleigh, North Carolina.

"Folks, I know I’m not a young man. But I know how to do this job. I know right from wrong. I know how to tell the truth," Biden said. "And I know, like millions of Americans know, when you get knocked down, you get back up."

Fox News' Paul Steinhauser and Emma Colton contributed to this report.