"Who is the 'lesser evil' that woman or that man?" the pope asked, referring to Vice President Kamala Harris and former President Donald Trump. "I do not know. Each person must think and decide in his or her conscience."

Pope Francis spent 45 minutes answering questions from 10 journalists on his flight Sept. 13 from Singapore to Rome at the end of a 12-day trip. He was asked about the four countries he visited, about sexual abuse, about his future travel plans, about the war in the Holy Land and the Vatican's relations with China.

A U.S. television reporter asked him about the choice Catholic voters face between Harris, who supports legalized abortion, and Trump, who wants to severely restrict immigration and has said he wants to deport millions of migrants.

Both attitudes "are against life: the one who wants to throw out the migrants and the one who kills children," the pope said. "Both are against life."

In the Old Testament, he said, God's people are repeatedly reminded to care for "'widows, orphans and the stranger,' that is, the migrant. They are the three that the People of Israel must protect. The one who does not care for migrants is lacking; it is a sin."

And "to have an abortion is to kill a human being. Whether or not you like the word, it is killing," the pope said. "The Catholic Church does not allow abortion because it is killing. It is assassination. And we must be clear about that."

Pope Francis was asked if there were situations when a Catholic could vote for a candidate who was in favor of abortion.

"In political morality, generally, they say not voting is wrong; one must vote, and one must choose the lesser evil" in accordance with one's conscience, he said.

Abortion and care for migrants are both issues the U.S. bishops urge Catholics to consider when voting. In their document, "Forming Consciences for Faithful Citizenship," however, they say, "The threat of abortion remains our pre-eminent priority because it directly attacks our most vulnerable and voiceless brothers and sisters and destroys more than a million lives per year in our country alone."

At the beginning of Pope Francis' trip, a French writer started a rumor that the pope would travel to Paris Dec. 8 for the reopening and consecration of the altar in Notre Dame Cathedral, rebuilt after a devastating fire in 2019.

When asked about that trip, the pope's response was simple: "I will not go to Paris."

As for the idea of the 87-year-old pope making a trip to Argentina, his homeland, he was not as clear.

"That is something that still hasn't been decided," he said. "I would like to go. They are my people. But there are various things to resolve first."

However, if he does go, he said, he would want to stop over in the Canary Islands, a Spanish autonomous region in the Atlantic, where thousands of migrants -- including many unaccompanied minors -- have arrived from Senegal, Mali and other African countries.

Regarding the ongoing clerical sexual abuse scandal, Pope Francis was asked about new revelations in the case of Abbé Pierre, the French priest and founder of the Emmaus Community, who died in 2007 at the age of 94.

As the pope's trip began, the Emmaus Community announced that new accusations of sexual abuse of women and children had been made against the priest, and French media reported that church officials and leaders of the community had tried to cover up allegations as far back as the 1950s.

"We must speak clearly on these things and not hide them," the pope said. "Abuse, in my judgment, is something diabolical" because it attacks the sacredness and God-given dignity of another person.

At that point in the Singapore Airlines flight, the pilot interrupted Pope Francis and announced over the loudspeaker that everyone should return to their seats and fasten their seatbelts.

"Your question created some turbulence," the pope quipped to the reporter.

Nevertheless, the pope remained on his portable chair in the center aisle and continued answering questions.

"The sexual abuse of children, of minors, is a crime," he said.

After answering two other questions, Pope Francis returned to the topic of Abbé Pierre to tell the reporter, "I don't know when the Vatican came to know about it. I don't know because I wasn't here, and I never thought to research it, but certainly after his death -- that is certain."

On the Vatican's relationship with China, the pope said, "I am content with the dialogue with China. The results are good. Also, on the nomination of bishops, the work is going forward with goodwill."

In 2018, the Vatican and the government of China signed an agreement outlining procedures for ensuring Catholic bishops are elected by the Catholic community in China and approved by the pope before their ordinations or installations. The provisional, two-year agreement, already renewed in 2020 and 2022, is up for renewal in October.

The text has never been made public, but the Vatican has complained a couple times in the past six years when China named or transferred bishops in apparent violation of the accord.

The pope also said he welcomed China's efforts to encourage a peaceful settlement of the fighting in the Gaza Strip.

"I call the parish in Gaza every day, every day," he said; inside the compound of Holy Family Parish, some 600 people -- Christians and Muslims -- have taken shelter.

Pope Francis said he could not judge whether Israel's reaction to the Hamas invasion in October is excessive, "but, please, when you see the bodies of children who have been killed -- when you see that because of a presumption that there are some guerrillas there they bomb a school -- it's awful, awful."

"Sometimes," he said, "a war is just too much, too much."