"I haven't been about say this until now and I only found out three years ago — but I've known since then — and it was most appropriate to respond to her and tell her I love her, which I do," Cohen said in a video posted by CBS News.
"There's been much written and said about my tweeting a very beautiful 24-year-old woman during the State of the Union address. And while I was concentrating on the president's remarks, I was also tweeting to my constituents and during that time the lady tweeted me and said that she saw me on television," Cohen said.
Cohen said he was "pleased" to have a "better, more open relationship" with his daughter, since she had let people know of their relationship.
"She has a private life, I have a public life and it's been hurtful to her to have things said about her on tweets and on comments and on scurrilous publications suggesting some type of inappropriate March, November relationship," he said.
NBC News’s Luke Russert first reported the woman was Cohen's daughter on Thursday in a message on Twitter, writing that the congressman “only learned of her 3 [years] ago.”
Cohen’s spokesman, Michael Pagan, confirmed the news with The Hill's ITK. Pagan said his 63-year-old boss revealed the paternity news to his staff in a Thursday evening meeting just 15 minutes before talking to the media.
"I'm very proud and happy to have a 24-year-old, beautiful, sweet, loving daughter, but I haven't been about to talk about it publicly, because it wasn't known to others that our relationship and it had been kept secret all these years," Cohen added.
Read more on The Hill's In The Know blog.
—Judy Kurtz contributed.