ROME — Pope Francis has revealed in an interview published Sunday that shortly after being elected pontiff in 2013 he wrote a resignation letter in case medical problems impede him from carrying out his duties.

Speaking to the Spanish newspaper ABC, Francis said he gave the note to Cardinal Tarcisio Bertone, who then was the Vatican secretary of state. The pontiff added that he presumes that the prelate currently in that Vatican No. 2 role, Cardinal Pietro Parolin, now has the written instruction.

Francis, who turned 86 on Saturday, had surgery in 2021 to repair a bowel narrowing and has been hobbled by knee pain that for months saw him use a wheelchair. Lately, he has increasingly used a cane instead of the wheelchair to get around in public.

Asked what happens if health issues or an accident suddenly leaves a pope unable to do his job, and whether there should be a rule for such instances, Francis replied, "In practice there is already a rule."

"I have already signed my renunciation," Francis revealed, noting that he did so early in the papacy.

"I signed it and said: 'If I should become impaired for medical reasons or whatever, here is my resignation. Here you have it,'" he said, referring to Cardinal Bertone, who stepped down as secretary of state in October 2013, in the first months of Francis' papacy.

The pontiff quipped that now that he has revealed the existence of his resignation note, "someone will run up to Bertone (saying), 'Give me that piece of paper.'"

Francis said he was sure Bertone would have passed on the letter to the current secretary of state, Parolin.

In past remarks, Francis has hailed the decision of his predecessor, Pope Benedict XVI, to resign because he felt due to advancing age he wouldn't be best able to carry out his duties. Benedict, who is living in a monastery on the Vatican's grounds, was the first pontiff to resign in 600 years, and his stepping down paved the way for Francis' election as the first pope from South America.

Francis in the interview played down his mobility challenge, saying "One governs with the head, not the knee."

Catholic church law requires a papal resignation be "freely and properly manifested" — as was the case when Benedict startled the world when he announced his resignation to a gathering of prelates at the Vatican in February 2013.