The Vatican's decision to uphold its conviction of the U.S. territory's ousted Archbishop Anthony Apuron for sexually abusing minors marks a sorrowful chapter in church history, the current archbishop of Guam, Michael Byrnes, said.

"The church does not rejoice when members of the church plummet from grace and are found guilty of grave wrong. In this case, egregious sin of child abuse. It's a deep and sorrowful shame," Byrnes said at a news conference in Guam on Friday.

While the Vatican exiled Apuron from the Pacific island and barred him from presenting himself as a bishop, it stopped short of defrocking him. The Vatican announced the decision Thursday. It cannot be appealed.

"As a church, what we can do in all cases of this kind is to forthrightly acknowledge sin to mete out penance and punishment of the sinner for his own salvation," Byrnes said. "On our part, we'll do everything in our power to ensure that this horrible harm inflicted to the innocent is never repeated.

"I extend our deepest apologies to the local men and their families who suffered irreparable harm by Anthony Apuron in the past."

Byrnes apologized to the victims and their families.

"I will pray for my brother, Anthony, too, as I do for his victims. With humility, I ask for the faithful to also assist Bishop Apuron in prayer and penance, that he may find grace in repentance and mercy for his soul."

Victims and their advocates denounced the sentence as inadequate. The ousted bishop continues to maintain his innocence.