ROME – Pope Francis acknowledged Saturday that in the wake of a grueling five-day trip to Canada, his ongoing health challenges, including osteoarthritis of the right knee, may force him to “save [my energies] a bit to be able to serve the Church,” or alternatively, to “think about the possibility of stepping aside.”

The comments came during an inflight news conference as Francis returned to Rome from his outing to Canada, the aim of which was to promote healing and reconciliation with the country’s indigenous population after revelations of abuse at church-run residential schools.

“I don’t think I can go with the same pace of the trips as before. I think at my age and with this limitation, I have to save [my energies up] a bit to be able to serve the Church or, on the contrary, think about the possibility of stepping aside,” Francis said, according to a transcript posted by Vatican News, the Vatican’s state-sponsored news agency.

“This [I say] with all honesty: it is not a catastrophe, you can change Pope, you can change, no problem! But I think I have to limit myself a bit with these efforts,” he said.

“I will try to continue to go on trips and be close to people, because I think it is a way of service, closeness,” the pope said.

“When the Lord speaks, if the Lord says go ahead, you go ahead, if the Lord says, go to the corner, you go to the corner,” Francis added.

On the subject of resignation, the pope also said, “The door is open, it’s a normal option, but until today I haven’t knocked on this door, I haven’t said it’s going to go in this room, I haven’t heard to think about this possibility. But that doesn’t mean the day after tomorrow I don’t start thinking, right? But right now I honestly don’t.”

“It is true that you cannot make trips in this state, you have to maybe change the style a little bit, decrease, pay off the debts of the trips you still have to make,” he said.

Asked about future trips, Francis indicated a willingness to travel but also concerns about his capacity. To date, there’s been speculation that Francis might go to Ukraine to demonstrate concern for the war, and to Kazakhstan for a Congress of Leaders of World and Traditional Religions scheduled for September.

In addition, Francis also was compelled to postpone a trip to South Sudan and the Democratic Republic of Congo earlier in July, and questions have been asked about when they might be rescheduled.

“I would like to go to Ukraine. Let’s see now what I find when I see at home,” the ope said Saturday.

“Kazakhstan, for the moment, I would like to go: it’s a quiet trip, without so much movement, it’s a congress of religions there. But for the moment, everything stays. Also, I have to go to South Sudan before Congo, because it’s a trip with the Archbishop of Canterbury and the Bishop of the Church of Scotland, all three together as all three of us did the retreat two years ago. Then, Congo. But it will be next year, because the rainy season … but, let’s see: I have all the good will, but let’s see what the leg says.”