Former Vice President Joe Biden’s claim that “poor kids are just as bright and just as talented as white kids” led New York City mayor and Democrat presidential hopeful Bill de Blasio to take to Twitter on Friday to state that Biden’s words are “concerning” and should not be dismissed.

“‘Poor’ kids are just as bright and talented as white kids?” de Blasio questioned in a tweet. “To quickly dismiss @JoeBiden’s words as a mere ‘slip of the tongue’ is as concerning as what he said”:

“Poor” kids are just as bright and talented as white kids? To quickly dismiss @JoeBiden’s words as a mere “slip of the tongue” is as concerning as what he said. We need to have a real conversation about the racism and sexism behind “electability.” https://t.co/PcL6OgMPnD — Bill de Blasio (@BilldeBlasio) August 9, 2019

De Blasio added, “We need to have a real conversation about the racism and sexism behind ‘electability.'”

Biden made the racially insensitive remarks while addressing the Asian and Latino Coalition in Des Moines, Iowa, on Thursday:

Joe Biden: “Poor kids are just as bright and just as talented as white kids.” pic.twitter.com/YhDSMnoRce — Trump War Room (@TrumpWarRoom) August 9, 2019

“We should challenge these students. We should challenge students in these schools to have advanced placement programs in these schools,” Biden said while discussing America’s education system. “We have this notion that somehow if you’re poor, you cannot do it. Poor kids are just as bright and just as talented as white kids.”

Attempting to clarify his remarks, Biden added “wealthy kids, black kids, Asian kids” to the end of his previous sentence.

Earlier this week, a poll revealed that President Donald Trump has a higher favorability rating in New York than de Blasio, who is currently polling at zero or one percent in several polls.