Updated at 10:13 p.m. ET on 7/23
(CNN) - With his wife by his side, New York mayoral candidate and former congressman Anthony Weiner said Tuesday that some of the sexually explicit online exchanges that were published by a gossip website happened after his resignation from the U.S. House in 2011.
"Some of these things happened before my resignation, some happened after," Weiner said at a hastily organized press conference in New York, where he also pushed back when asked if the latest revelation would prompt him to drop out of the race.
His remarks came hours after screenshots of sexually charged conversations and photographs appeared on a gossip website which alleged the communications were between Weiner and a young woman last summer.
Weiner resigned his House seat in New York after admitting to sending lewd photographs and images to multiple women.
In an extraordinary move, Weiner's wife, Huma Abedin, appeared beside her husband Tuesday and made brief remarks backing him.
"What I want to say is I love him, I have forgiven him, I believe in him, and as I have said from the beginning, we are moving forward," said Abedin, a top adviser to Hillary Clinton, adding that Weiner had made some "horrible mistakes, both before he resigned from Congress, and after."
PHOTOS: Weiner addresses lewd exhanges
Weiner resisted calls from some of his rivals for the Democratic mayoral nomination to give up his bid, adding, "I'm sure many of my opponents would like me to drop out of the race."
The New York chapter of the National Organization for Woman called on Weiner to withdraw from the race following his press conference.
"As if we didn't already have enough evidence of Anthony Weiner's utter lack of judgment, impulse control and honesty, these latest revelations show the degree to which his candidacy distracts us from the important business of choosing the next leader of New York City," Sonia Ossorio, the president of the group, wrote in a statement.
The editorial board of the New York Times followed suit, writing "At some point, the full story of Anthony Weiner and his sexual relationships and texting habits will finally be told. In the meantime, the serially evasive Mr. Weiner should take his marital troubles and personal compulsions out of the public eye, away from cameras, off the Web and out of the race for mayor of New York City."
Earlier in the day, Weiner released a statement admitting that some of the conversations and photos that appeared on the website TheDirty.com were his.
"While some things that have been posted today are true and some are not, there is no question that what I did was wrong," Weiner said.
In the statement, Weiner pointed to previous comments he made around the time he announced his bid for New York City mayor, in which he said it was possible for more photos to come out as he made a re-entry into politics.
"I said that other texts and photos were likely to come out, and today they have," he said Tuesday.
The exchanges that surfaced Tuesday were revealed about a year after they allegedly took place and in the middle of Weiner's Democratic primary campaign for New York mayor.
"This behavior is behind me. I've apologized to Huma and am grateful that she has worked through these issues with me and for her forgiveness," he said.
In facing reporters, Weiner was supported by his wife, who in emotional comments discussed the couple's struggles to save their marriage.
"I made the decision that it was worth staying in this marriage," she said. "That was a decision I made for me, for our son, and for our family."
"This was the first time we heard his wife, Huma Abedin, speak at a press conference, but also speak about these issues," CNN Chief Congressional Correspondent Dana Bash said. "This wasn't just a scene of a wife standing by her political man. This was a wife coming up to the cameras, coming up to the microphones, and talking, which was frankly extraordinary. She is somebody who isn't just a wife. She is very politically savvy."
"Maybe most importantly, she learned at the knee of Hillary Clinton, somebody who most famously stood by her man politically. And so she's following in those footsteps,” Bash continued.
As Weiner's latest scandal unfolded, Harper's Bazaar published excerpts of an article Abedin wrote for the magazine.
"Three years ago I was a single workaholic, traveling the globe with an amazing job at the U.S. State Department. I could not have imagined how much my life would change in three short years," Abedin wrote for the magazine's September issue.
"Today I'm married, with a feisty 20-month-old son, a full-time job, and a husband running for mayor of New York."
Abedin said she has kept her personal life private for years, and no one is more surprised than she is to see herself on the campaign trail.
"So why am I doing this? Because Anthony has always been a smart, caring, and dedicated person, and while he's the same public servant who wants what's best for the people he represents, he is now something else-a better man," Abedin wrote.
Weiner’s public remarks came after chat messages purporting to be from Weiner were published on the website TheDirty.com. The post cited a "solid" source alleging Weiner engaged in lewd online conversations with her, and reproduced lengthy chats that were sexual in nature.
The woman, 22, says Weiner vowed to secure her a place on a panel hosted by Politico, as well as purchase a condominium for her in Chicago.
"I just want people to really know he's lying when he acts like he has changed," the unnamed woman told TheDirty.
In one instance, an explicit photo was published that the site claimed Weiner sent to the woman online. The name Weiner used online was "Carlos Danger," according to TheDirty.com
Weiner, who represented parts of Brooklyn and Queens, resigned from Congress after admitting to sending lewd photographs to multiple women online. At first he hedged on whether the photos were of him, including in an interview with CNN's Wolf Blitzer.
"It certainly doesn't look familiar to me, but I don't want to say with certitude to you something that I don't know to be the certain truth," Weiner said at the time.
After more reports of online exchanges with other women surfaced, fellow Democrats encouraged Weiner to resign, which he ultimately did after confessing to the indiscretions.
In the run-up to his mayoral bid, which he launched in May, he said more photos could emerge.
"If reporters want to go and try to find more, I can't say they're not going to be able to find another picture, find another person who may want to come out on their own," he told RNN Television. "But I'm not going to contribute to that. The basics of the story are not going to change. It's behind me. It was a huge mistake."
Polls taken over the past several weeks have shown Weiner either leading his closest rival for the Democratic mayoral nomination, City Council Speaker Christine Quinn, or trailing her in second place.