Jill Biden joked about her husband's title mix-ups when she introduced Kamala Harris as 'president.'

During a White House event to mark Black History Month, the first lady said: "Ladies and gentlemen, the president of the Uni… the vice president."

This caused a chorus of laughter and applause in the room in response while the real president, Joe Biden was able to see the funny side of the joke as he looked over towards Harris and then proceed to lift up his arms and bow his head in pretend defeat.

Dr Biden then explained the reason behind her misspeaking: "I just said to make you laugh."

The joke was in reference to the president mistaking Harris’ job description, most recently during an appearance in January to remember Martin Luther King Jr.

"Last week, President Harris and I stood on the United States Capitol," President Biden said during his speech at the Atlanta University Center Consortium.

He also referred to "President Harris" again back in December at a graduation speech at South Carolina State University and once more in March 2021.

It comes as a new poll from ABC News/The Washington Post shows 54 per cent of Americans are concerned President Biden doesn’t have the “mental sharpness it takes to serve effectively as president."

Sign up to our newsletters here.

Up next Politics