The New York City fire commissioner's son resigned from his EMT job Monday after racist and offensive Twitter posts drew headlines and forced an apology from his father, the department said.

Joe Cassano, 23, son of FDNY Commissioner Salvatore Cassano, left his job after just three months over the tweets, city officials said.

The commissioner said he was disappointed with his son's behavior and that the resignation was the "right decision."

"I am extremely disappointed in the comments posted online by my son Joseph, which do not reflect the values -- including a respect for all people -- that are held by me, my family and the FDNY," Cassano said in a statement.

"There is no place -- and I have no tolerance -- for statements that would harm the good reputation we enjoy due to our honorable service to all New Yorkers," the commissioner said.

The elder Cassano added: "As a parent, this is very painful for me, but I believe my son has made the right decision. I love him very much and, with the support and love of our entire family, we will get through this together."

Mayor Michael Bloomberg said in a news conference Monday morning that he "found the message offensive" and that he also agreed with the resignation.

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"It is my understanding that he has chosen to resign from the fire department," Bloomberg told reporters. "I think that's the appropriate thing, and I'll leave it there."

The younger Cassano had sent anti-Semitic and racist tweets from his Twitter account, which has since been taken offline.

The tweets were published by the New York Post Monday, prompting the quick resignation.