Former U.S. Ambassador to the U.N.Nikki Haley fired back at Democratic presidential candidate Joseph R. Biden in a tweet Wednesday after the former vice president appeared to criticize her intellect during a campaign rally in South Carolina.

“Hold up Joe. I will put my brain up against yours anytime. Bring it. #GodBlessJoe,” Ms. Haley, the former governor of South Carolina, tweeted Wednesday afternoon.

The former ambassador was referring to a report by The Post And Courier’s Jamie Lovegrove, who said Mr. Biden corrected himself after appearing to question Mrs. Haley’s “brains.”

“Biden has started criticizing @NikkiHaley more directly in South Carolina recently for declining to expand Medicaid here,” Mr. Lovegrove reported in a tweet. “In Georgetown, he appears to start saying she ‘didn’t have the brains’ before stopping himself and changing it to ‘foresight’ because he wants to ‘be polite.’”

Mr. Biden has always been known for his gaffes but they’ve been coming under increasing scrutiny as his campaign continues. Just Monday he declared himself “a Democratic candidate for the United States Senate.”

Earlier Wednesday, Ms. Haleykicked off the American Conservative Union’s Conservative Political Action Conference in suburban D.C. by declaring President Trump is ready to take on whomever the Democratic Party chooses as its nominee.

“You know what [Democrats] have forgotten? They’ve forgotten what I learned at the United Nations, which was every socialist country that we ever came in contact with wanted to be in America,” Ms. Haley said. “They wanted what we had: They wanted freedom of religion, they wanted freedom of speech, they wanted freedom.”

She did not directly respond to calls for her own presidential campaign.