An appointee tapped to lead New York Mayor-elect Zohran Mamdani’s recruitment efforts resigned Thursday after antisemitic social media posts resurfaced.

Catherine Almonte Da Costa resigned a day after Mamdani named her director of appointments, with responsibilities to strategize recruitment in his administration.

“I spoke with the Mayor-elect this afternoon, apologized, and expressed my deep regret for my past statements. These statements are not indicative of who I am,” Da Costa said in a statement through Mamdani’s transition team.

“As the mother of Jewish children, I feel a profound sense of sadness and remorse at the harm these words have caused. As this has become a distraction from the work at hand, I have offered my resignation,” she added.

In remarks after Mamdani announced her appointment Wednesday, Da Costa had described “building a government that is both mission-driven and deeply capable, a government staffed by diverse leaders with the skill and the experience to turn vision into results” and recruiting talent “to reflect the rich diversity of race, faith, geography, language and ethnicity that defines the city.”

The social media posts, which were first reported by the Judge Street Journal, a New York politics newsletter, date back more than a dozen years. They were first published by the Anti-Defamation League’s New York and New Jersey chapter.

In a 2011 post from a now-deleted account on Twitter, now known as X, Da Costa referred to “money hungry Jews,” and in a post the following year she wrote that “Far Rockaway train is the Jew train,” according to the newsletter.

The Anti-Defamation League did not immediately respond to a request for additional comment Thursday night.

The group’s New York and New Jersey chapter wrote on X that Da Costa’s old posts “echo classic antisemitic tropes and otherwise demean Jewish people.”

“Tweeting about ‘Money hungry Jews’ is indefensible,” the chapter said. “We appreciate Da Costa has relationships with members of the Jewish community, but her posts require immediate explanation — not just from Ms. Da Costa, but also from the Mayor-Elect.”

Mamdani said in a statement that “Catherine expressed her deep remorse over her past statements and tendered her resignation, and I accepted.”

A Mamdani spokesperson told NBC News that the posts were not detected during the transition’s vetting process.

On the campaign trail, Mamdani, who will be the city’s first Muslim mayor when he is sworn in on Jan. 1, sought to defend himself against allegations of antisemitism, particularly as it related to his criticism of the Israeli government and claims from opponents that he did not have a plan to combat antisemitism in the city.

Da Costa’s resignation follows calls from Jewish groups in the United States for bolstered security at public events to guard against acts of antisemitism.

Last weekend, two gunmen opened fire at Bondi Beach in Australia during a Hanukkah celebration. The surviving suspect faces charges that include terrorism and murder in connection with the fatal shooting of 15 people. The suspect’s lawyer did not enter any pleas during a video court appearance Wednesday, The Associated Press reported.

Zoë Richards is a politics reporter for NBC News.