Archbishop Salvatore Cordileone of San Francisco sharply criticized the state of Delaware on Wednesday, saying the state's new marriage equality law would harm children.

"The claim of this bill to redefine marriage is in vain; marriage cannot be redefined, because its unique meaning lies in our very nature. It is also a serious injustice to the most vulnerable among us: children," Cordileone, the chairman of the U.S. Conference of Catholic Bishops’ Subcommittee for the Promotion and Defense of Marriage, said.

He also said Rhode Island's new same-sex marriage law was "a serious injustice" last Friday.

Delaware on Tuesday became the eleventh state to allow gay and lesbian couples to marry. Same-sex couples in Delaware will be able to officially tie the knot starting on July 1.

"Marriage is the only institution that unites a man and a woman to each other and to any child conceived of their union," Cordileone said. "Our society either preserves laws that respect the fundamental right of children to be raised by their moms and dads together in marriage, or it does not."

Same-sex marriage has gained traction in the United States and around the world despite Catholic opposition. Minnesota is expected to legalize same-sex marriage next week, and Illinois could later follow suit.