By Philip Pullella
Pope Francis has appeared to open the door to a possible limited softening of the Roman Catholic Church's ban on contraception because of the Zika virus.
But the Argentine pontiff, speaking to reporters as he flew back to Rome from a visit to Mexico, categorically ruled out abortion as a response to Zika, comparing the practice to a mafia killing.
The health crisis has put pressure on Church teachings, particularly in Latin America, where abortion is now being debated more openly even in some conservative countries.
Many scientists believe Zika, a mosquito-borne disease that is currently sweeping through the Americas, may be a risk factor for microcephaly in newborns - a condition in which babies are born with abnormally small heads.
In the freewheeling, post-trip news conference that has become a trademark of his papacy, the pope was asked if using contraception would fall into the category of the lesser of two evils and how he felt about some authorities advising pregnant women with Zika to have abortions.
He categorically ruled out that abortion would ever be permitted for pregnant women with Zika who fear that they may give birth to a child with microcephaly.
"Abortion is not a lesser evil. It is a crime. It is killing one person to save another. It is what the mafia does," Francis said, speaking passionately against the practice. "It is a crime. It is an absolute evil."
The 1.2 billion-member Church teaches that abortion is a crime because life begins at the moment of conception. The Church teaches that contraception is wrong because nothing should block the possible transmission of life.
But Francis mentioned in his response that one of his predecessors, Pope Paul VI, had issued an exceptional dispensation allowing nuns in Africa to use the birth control pill because they risked being raped during a conflict there.
He said Paul, who reigned from 1963 to 1978, had responded to "a difficult situation in Africa", suggesting that a papal precedent existed.
Francis said that unlike abortion, "avoiding pregnancy is not an absolute evil" and added that "in certain cases", such as the precedent set by Paul VI regarding the nuns in Africa, using contraception might be the "lesser evil".
He did not elaborate.