Pope Francis said he is focused on fighting corruption in the Catholic Church, despite the challenges.
"I know I have to do it (fight corruption), I was called to do it, but it will be the Lord to decide if I did well or not. Sincerely, I am not very optimistic," he said during an interview Friday with Italian news agency AdnKronos.
Pope Francis also said he is not deterred by criticisms in whatever area, noting he takes them "on board because it can lead to self-examination." He added he will not let himself be "dragged down by every non-positive thing written about the pope."
In 2013, Pope Francis was elected by cardinals on a mandate to clean up the Vatican's finances, after a series of corruption scandals.
Last month, Francis fired a former top Vatican official, Cardinal Angelo Becciu, for alleged embezzlement in the purchase of a luxury London building for the Vatican. Becciu has denied all accusations.
A former worker of Becciu, 39-year-old Cecilia Marogna, was released Friday after spending at least two weeks in jail. Marogna is awaiting a judge's decision on extradition from the Vatican.
Francis says he is worried the "cases of malfeasance, of betrayals" hurt believers of the Catholic faith.