The Vatican is facing mounting criticism for not taking a more heavy-handed approach to sexual abuse allegations after accepting the resignation of Cardinal Donald Wuerl but allowing him to remain influential in the church.

Pope Francis issued a letter Friday saying he would accept the resignation of the archbishop of Washington, D.C.,in response to accusations that he did nothing to stop abuse by senior clerics in Pennsylvania where he served as a bishop from 1988 to 2006.

While some church leaders and parishioners have called for Wuerl's resignation in recent weeks, critics point to the fact that Francis asked Wuerl to remain the apostolic administrator of the archdiocese. He will also attend the annual American bishops meeting slated for November and holds an influential role on the Congregation of Bishops, which chooses who will take roles of church leadership.

Wuerl will no longer serve as leader to more than 650,000 Catholics in Washington, but he's still expected to retain significant influence as a member of the Congregation for the Doctrine of the Faith, which over sees Vatican theology.

The Vatican did not immediately respond to NBC News' request for comment.

In sharing his disappointment with the Vatican, Pennsylvania Attorney General Josh Shapiro referred to details in a Pennsylvania grand jury report that alleged Wuerl was able to cover up abuses in the Pittsburgh diocese.

"He is now able to retire seemingly with no consequences for his actions," Shapiro said at a news conference on Friday.

The report released two months ago found that more than 300 priests in the state sexually abused minors over a 70-year period. Wuerl, 77, was not accused of abuse but was named several times throughout the report. A key ally of Francis, he has been the most prominent figure to take the fall since the report was released.

Shapiro has been championing legal reforms recommended by the grand jury to remove the statute of limitations on child sexual abuse claims in order to convict perpetrators decades later. The attorney general said Friday that he is focusing on strengthening the law to support victims seeking justice and prevent future cases of abuse.

"I think we've learned in this process that we can't rely on the church to fix itself," he said.

While Francis accepted the resignation, the letter thanks Wuerl for not taking a defensive approach to justify "some mistakes" he may have made.

"[You] make clear the intent to put God's Project first, before any kind of personal project, including what could be considered as good for the Church," it says.

A group representing survivors of the scandal said the Vatican should be admonishing church leaders that covered up abuse and the letter minimizes the impact Wuerl's actions had on victims. "This is another knife in the heart of those who have already suffered at the hands of the Catholic church," said Survivors Network of those Abused by Priests in a statement.

Mitchell Garabedian, who has represented numerous clergy sex abuse victims including those involved in the Catholic Archdiocese of Boston sex abuse scandal, said the pope had not gone far enough. Based off Francis's statement, he noted that it would be unsurprising if Wuerl were given a promotion to a Basilica in Rome as was the case with Cardinal Bernard Francis Law, who was accused of covering up decades of abuse in Boston.

"Instead of portraying Cardinal Wuerl as a victim who made some mistakes, Pope Francis should be instructing Cardinal Wuerl to fully reveal Cardinal Wuerl’s role in the cover up while Bishop of the Diocese of Pittsburgh for about 18 years and in the scandal involving former Cardinal McCarrick so that victims can try to heal," he said, referring to disgraced Cardinal Theodore McCarrick. "Pope Francis’s portrayal of Cardinal Wuerl adds another layer to the cover up."

Garabedian said all should remember that numerous state attorneys general have opened investigations into the Catholic Church and sex abuse.

“Momentum is building,” Garabedian told NBC News. “What happened in Boston and Pennsylvania is causing many other states to investigate the criminal activities concerning pedophilia within the church and a domino effect is taking place.”

And that's an encouraging sign, according to Garabedian, who emphasized that the abuse and the cover up are both criminal acts.

"Take away their robes and religion and we have one of the biggest criminal enterprises in the world," he said. "We’re talking about sexual abuse of thousands of children in wholesale fashion for decades upon decades while thousands of priests and supervisors covered it up — they’re criminals. They belong in jail."