Pontiff told Mexican TV "Those who build walls end up being prisoners of the walls they build."
"Is it licit to throw away a life to resolve a problem?" he asked. "Is it licit to hire a hitman to resolve a problem?"
The pope said that whistleblowers would be granted protection and that dioceses worldwide would be required to have a system in place to preserve the anonymity and confidentiality of those submitting claims.
"A pope who is guilty of heresy and remains obstinate in his heretical views cannot continue as pope," the letter signed by 19 priests and theologians says.
Alain de la Morandais said of church abuse: "We always have the impression that it is a rape, that there is violence. But I do not always think so."
Pope Francis said people can't spend their whole lives accusing the church of wrongdoings.
"That is not a Christian gesture," the pope has said about the president's claim that Mexico would pay for the wall.
"May the Lord help us to put out the hotbeds of hate that flare up in our societies," Pope Francis said on Sunday, mourning the victims of Saturday's shooting at a synagogue in Pittsburgh.
Oscar Romero was shot dead in San Salvador in March 1980.
Pope Francis made the remarks during an address to worshippers in the Vatican.
"Many young people do not turn to us for anything because they don't feel we have anything meaningful to say," the Pope conceded.
Reverend Paul Kalchik's actions sparked protests from LGBT activists last week.
American clergy met with the pope at the Vatican to discuss the sex abuse crisis in the church.
The media's attempts to cover for Francis because of their love for his politics is vile.
Only 130,000 people arrived Sunday to see Pope Francis's mass in Dublin, amid large-scale protests against child sex abuse in the church.
A former high-ranking Vatican official says that Pope Francis covered up allegations of sexual abuse in the church
The Pope's visit is not without controversy.
While still predominately Catholic, Ireland has voted to legalize abortion.
The publicity stunt promises "an express lane to eternal salvation for Ireland's lapsed Catholics."
The pope issued a letter to Catholics in response to the Pennsylvania grand jury report that implicated hundreds of clergy members in the sexual abuse of more than 1,000 children.
One of the more than 1,000 victims violated by Catholic priests decades ago comes forward to tell her story to Newsweek.
Attorney General Josh Shapiro requested that the court release the names of priests included in the 31-page document.
Pope Francis initially called the allegations against Bishop Barros "slander."