Opening up a culture war on another front this weekend, US Catholic Church leaders have just been warned by Pope Benedict to strongly oppose every measure that could lead to the federal legislation of marriage rights for same sex couples here.

It's the latest anti-gay marriage salvo from the 84-year-old Pope, who on Friday denounced unnamed but 'powerful political and cultural currents' here whose aim is to legalize gay marriage in the United States.

In a report in the Huffington Post on Friday the pope said that the traditional family and traditional man woman marriage must be 'defended' because same sex marriage 'injures' families and injures society. The pontiff did not outline exactly how traditional families are injured, however.

Benedict then called on American bishops to 'defend' marriage and  'procreation' from attacks by homosexual couples wishing to be married. Earlier this year the pope claimed that same sex marriage would 'threaten the future of humanity.'

Critics contend that gays are a part of humanity, not a threat, and that the church is ratcheting up the rhetoric in an attempt to scare the public, based on the premise that frightened people are easier to manipulate in an election year.

Meanwhile Cardinal Dolan, also a same sex marriage foe, made headlines this week when he released details of the head-to-head he's been conducting with the Obama administration over health care access to contraception. Both leaders now appear be assailing the administration with hardline, hot button issues.

Groups of visiting U.S. bishops have been traveling to Rome for the past several months as part of the bishops’ once-every-five-year visits with the pope and with senior Vatican officials.