Weiner confirmed that his campaign manager, Danny Kedem, resigned Saturday after reports surfaced that Weiner exchanged lewd photos and messages with women despite resigning from Congress over the same behavior two years ago.
Weiner continued campaigning on Sunday and spoke at a Brooklyn church. He said it's not "about the people working on the campaign. It's about the people we're campaigning for."
Weiner had been a frontrunner in the mayor race before the latest revelations. Other politicians and his fellow candidates have called for him to end his campaign.
Last week, Weiner apologized and promised that the "behavior is behind me" after a gossip website printed X-rated excerpts of online conversation Weiner had with an Indiana college student last summer.
Weiner's wife, Huma Abedin, says she will continue to stand by her husband.
The Associated Press contributed to this report.