|Weiner, who refused to resign earlier, has now reportedly caved in to growing pressure
Embattled US Representative Anthony Weiner has resigned from the Congress in the wake of a scandal over inappropriate affairs that he had on the internet.
The 46-year-old Democrat made the announcement in New York on Thursday after fighting off pressure to step aside for two weeks.
Weiner said he cannot continue in office amid the intense controversy surrounding the sexually explicit messages he sent online to several women.
He reportedly reached the decision to resign after speaking with his wife, Huma Abedin, an aide to US Secretary of State Hillary Clinton who returned from an overseas trip on Tuesday.
Weiner apologised again for "the embarrassment that I have caused'' and said he hoped to continue to fight for the causes dear to his constituents. His wife was not with him for the announcement.
The New York congressman said earlier he would seek treatment and was granted a "short leave" of absence from the House.
Weiner was a leading liberal voice in the US House of Representatives, and had been expected to run for mayor of New York City in 2013.
His scandal began more than two weeks ago when Weiner denied tweeting a photo of a man's bulging boxer briefs to a 21-year-old female student in Washington state, insisting his account had been hacked.
He admitted to his online affairs a week after the controversy broke but refused to resign.
'A frivolous thing'
Weiner said his affairs were conducted over several years on Twitter, Facebook, email and by phone with women he met online, primarily on Facebook.
He said he sent the women explicit pictures of himself but broke no law, mostly used his home computer and never used his congressional mobile device.
He characterised his relationships with the women as "a frivolous thing" and admitted that the affairs were conducted both before and since he was married.
Calling his actions "very dumb" and "destructive," he stressed he did not have sex with any of the women.
After the scandal broke, House Democratic Leader Nancy Pelosi called for an ethics probe "to determine whether any official resources were used or any other violation of House rules occurred".