VATICAN CITY — Pope Benedict XVI asked bishops Saturday to ensure that religious teachings are authorised by the Catholic Church, in a bid to keep US Catholics in line with the Vatican.

The appeal comes after the Vatican last month upbraided a US association of Catholic clergy women for its feminist and liberal stances on contraception, homosexuality and female priests.

"Such discord harms the Church's witness and, as experience has shown, can easily be exploited to compromise her authority and her freedom," the pope said in a speech.

He referred to an article of Catholic rules that specifies clergy must receive approval from the Vatican for the contents of their teachings.

"The importance of this canonical norm ... becomes all the more evident when we consider the confusion created by instances of apparent dissidence between some representatives of Catholic institutions and the Church's pastoral leadership," the pope said.

Catholic leaders in the US are split between an ultra-conservative wing, which has slammed President Barack Obama's reforms that include contraceptive requirements in health care coverage, and other church leaders who have taken more liberal stances on homosexuality and other issues.

For the pope, who has been receiving groups of US bishops for regular work sessions, the rejection of abortion and euthanasia are "non-negotiables" that the Church must defend.