Mayor Michael Bloomberg is defending his decision to exclude religious leaders from New York City's commemoration of the Sept. 11, 2001, terrorist attacks, saying Friday that "government shouldn't be forcing" religion "down people's throats."

"It's a civil ceremony. There are plenty of opportunities for people to have their religious ceremonies," Mr. Bloomberg said on his weekly radio show. "Some people don't want to go to a religious ceremony with another religion. And the number of different religions in this city are really...