Pope Francis addressing worshipers May 8, 2019, at St. Peter's in the Vatican.
Aboard the Papal plane CNN  — 

Pope Francis says he is not afraid of a schism within the Catholic Church, even as he confronts criticism from conservative Catholics about his leadership.

“I pray that there will not be schisms,” the Pope said Tuesday, “but I am not afraid.”

The Pope’s remarks came in response to a question from a journalist at a press conference aboard the papal plane. Francis was returning to Rome from Africa, where he spent six days in Mozambique, Madagascar and Mauritius.

A schism is a formal break within the church, usually due to disputes over Catholic teaching.

“There have been many schisms in the Church,” Francis said, referring to the institution’s long history of religious disputes.

Last Wednesday, on the outbound flight to Africa, Pope Francis said it’s an “honor” when traditionalist American Catholics attack him.

But the criticism of Francis isn’t only coming from the United States, the Pope said on Tuesday.

“They are a little bit everywhere, even in the Curia,” he said, referring to the Vatican’s bureaucracy.

“At least those who criticize have the honesty to say it. I like that. I don’t like it when the criticisms are under the table and they smile and show their teeth and then there is a knife in the back. This is not loyal, this is not human.”

Francis also defended himself against accusations by some conservative Catholics that he is too liberal, saying that he is in line with other Popes like John Paul II.

“The Pope is too communist,” Francis said, paraphrasing some conservative sentiment against him.

“The social things that I said are the same that John Paul II said,” referring to the social teachings of the church on topics like economics, politics and the environment.

Francis suggested that some of those who attack him may have psychological problems and should be treated kindly.

“When you see rigid Christians, bishops, priests, you know there are problems there,” he said. “We need to be gentle with these people and accompany them.”

During his 10 days in Africa, the Pope focused mainly on three themes at the heart of his papacy: combating poverty, environmental degradation and political corruption.

CNN’s Daniel Burke contributed to this story.