The Vatican insisted Friday that it is properly following Christian tradition by excluding females from the priesthood as it issued a new warning that women taking part in ordinations will be excommunicated.
The move dashed the hopes both of women seeking to be priests and of Catholics who see that as an option for a church struggling to recruit men.
A top Vatican official said the church acted after what it described as "so-called ordinations" held in various parts of the world.
Monsignor Angelo Amato of the Congregation for the Doctrine of the Faith said the Vatican wanted to provide bishops with a clear response on the issue.
The church has always banned the ordination of women by stating that the priesthood is reserved for males. The new decree is explicit in its reference to women.
"The church does not feel authorized to change the will of its founder Jesus Christ," Amato said in an interview prepared for Vatican Radio that was released to reporters. The reference is to Christ's having chosen only men as his Apostles.
Asked whether the Roman Catholic Church was going "against the tide" in respect to other Christian confessions, Amato said the church was in "good company" with Orthodox and ancient eastern churches and that it was the Protestants who are breaking with tradition.
In March, the archbishop of St. Louis excommunicated three women — two Americans and a South African — for participating in a woman's ordination. They were part of the Roman Catholic Womenpriests movement, which began in 2002.
The decree was published Thursday by Vatican newspaper L'Osservatore Romano, which in a headline called the ordination of women a "crime."
The congregation said it acted to "preserve the nature and validity of the sacrament" of ordination.
The decree — signed by the congregation's head, American Cardinal William Levada — said anyone trying to ordain a woman and any woman who attempts to receive the ordination would incur automatic excommunication.
'Expressing their regrets'
Pope Benedict XVI led the doctrinal office before becoming pontiff in 2005. Like his predecessor, Pope John Paul II, he has consistently rebuffed calls to change traditional church teachings on divorce, abortion, euthanasia, gay marriage and the requirement that priests be male and celibate.
"We didn't expect anything different now, but in 20 to 30 years they will be expressing their regrets when they will need more priests," said Vittorio Bellavite, an Italian spokesman for the international reform group We Are Church.
The Vatican released figures this week showing that the number of priests increased slightly worldwide between 2000 and 2006, with the growth in Africa and Asia. It said the number remained stable in the Americas dropped nearly 6 percent in Europe.
Catholics who are excommunicated cannot receive the sacraments. Amato said the penalty can be lifted if those so punished are sincerely repentant.