His criticism echoes the reason Department of Education spokeswoman Jessica Scaperotti gave The New York Post for the program change.

“The lyrics are not age-appropriate,” she said of Lee Greenwood's patriotic ballad.

Grimm rejected the argument.

“I am outraged that NYC’s Department of Education is standing by the decision of PS 90’s principal to pull the song ‘Proud to be an American’ from the upcoming kindergarten ceremony, for fear of offending other cultures," Grimm said in a statement. "The fact that the principal nixed the performance of this patriotic, G-rated song while permitting an inane and age-inappropriate Justin Bieber song about teenage romance only underscores my concern about the skewed views being forced on these students."

The school's principal, Greta Hawkins, told teachers during a rehearsal for the graduation program that the song might "offend other cultures,” according to teachers who spoke to The Post.

“I have just one question for this principal: ‘Who exactly are we offending?’ " demanded Grimm, who represents the region in Congress. "The only thing offensive about any of this is the anti-American message being engrained in our youth. We all should be proud to be American and we should never ever apologize for it!"

The song had been planned for the graduation finale, and students had practiced for the program, including the song, for about five months, according to the paper.

The graduation ceremony is scheduled to take place June 20.