The Pope made his strongest comments yet against abortion in an address to global ambassadors on Monday.
"It is horrific even to think that there are children, victims of abortion, who will never see the light of day," he said in a speech delivered at the Vatican.
Since his election in March last year, Pope Francis has not spoken out against abortion as sternly or as often as his predecessors Pope Benedict XVI and the late John Paul II, who frequently likened abortion to murder.
Some have accused the Pope of being too liberal in the face of his reticence on the issue and after recently saying that the Church should not be so obsessed with abortion, gay marriage and contraception.
Last year, Bishop Thomas J Tobin of Providence, Rhode Island, criticised the Pope for not addressing "the evil of abortion" more directly.
However, the Pope made his views on abortion clear in his speech on Monday, saying it was the product of a "throwaway culture".
"Unfortunately, what is thrown away is not only food and dispensable objects, but often human beings themselves, who are discarded as unnecessary," the Pope said.
The comments echo a speech he made last September in which he said the unborn were among those in greatest need of the Church's protection, together with the elderly and the poor.
"Every unborn child, though unjustly condemned to be aborted, has the face of the Lord, who even before his birth, and then as soon as he was born, experienced the rejection of the world," he said.
"And every old person, even if infirm and at the end of his days, carries with him the face of Christ. They must not be thrown away!"
