The Vatican has formally approved new regulations to deal with cases of American priests involved in the sexual abuse of children.

The regulations approved Monday provide a system for investigating allegations of sexual abuse by American priests, and a framework for determining what punishment to impose, including possible dismissal from the priesthood. This document is stronger than the one originally proposed by the American Catholic Bishops, which the Vatican rejected in October as inadequate, confusing and ambiguous.

The new rules were worked out through a special commission formed by the Vatican and the U.S. Conference of Bishops. The approval came Monday in a letter to the American bishops from a senior Vatican official.

The letter stressed the Vatican will not tolerate sex abuse crimes against children by priests. It says the Vatican will be fully supportive of bishops' efforts to combat and prevent "such an evil." The letter calls child abuse "one of the most serious offenses" a priest can commit, and says it should be punished by "the most severe penalties."

The letter adds that the church must also defend the good name of the overwhelming majority of priests.

The new policy will be reviewed in two years.

Approval of the new regulations came just three days after Pope John Paul II accepted the resignation of Cardinal Bernard Law as archbishop of Boston. As the senior U.S. cardinal, he was at the center of the scandal over the American Catholic Church's response to a series of sex abuse charges against priests.

Documents published in January revealed that Boston church leaders had moved priests accused of sexual abuse to other parishes, rather than dismissing them. That practice would no longer be allowed under the rules approved on Monday.