Pope Francis described as "frightful" the fate of aborted children and lamented the "throwaway culture" of the world where even human beings are discarded, in a strong message to diplomats on Monday.
In his message to the Vatican diplomats, Francis stressed that peace is threatened by the denial of human dignity, whether it's in the form of ignoring hungry children or aborting or selling them.
"It is frightful even to think there are children, victims of abortion, who will never see the light of day; children being used as soldiers, abused and killed in armed conflicts; and children being bought and sold in that terrible form of modern slavery which is human trafficking, which is a crime against humanity," the Vatican leader told more than 180 ambassadors at the Holy See.
Pope Francis has previously spoken out against abortion, saying life at any stage is sacred.
In his first major written work last year, his "apostolic exhortation," Francis called for protecting the unborn, whom he described as "the most defenseless and innocent among us."
"Yet this defense of unborn life is closely linked to the defense of each and every other human right. It involves the conviction that a human being is always sacred and inviolable, in any situation and at every stage of development. Human beings are ends in themselves and never a means of resolving other problems," Francis wrote.
The Roman Catholic Church has seen both verbal and physical attacks by feminist groups who oppose the church's pro-life stance. In December, the group FEMEN crashed a Christmas service at a Catholic church in Cologne, Germany, with a topless activist exposing herself on top the altar with the words "I am God" written on her body.
This followed an incident in November in Argentina, where a pro-abortion group burned an effigy of Pope Francis in front of a Catholic cathedral, and sexually molested members of the church who were standing outside in prayer.
The Roman Catholic Church leader also highlighted on Monday "the greedy exploitation of environmental resources" as another major threat to peace, and said it is important to pursue policies that are respectful to the planet, calling it "our common home."
"I recall a popular saying: 'God always forgives, we sometimes forgive, but when nature – creation – is mistreated, she never forgives!' We have also witnessed the devastating effects of several recent natural disasters," Francis said, recalling the devastating impact of typhoon Haiyan in the Philippines and Southeast Asia, which killed over 6,000 people.
Pope Francis' full letter to the diplomats can be read on the Vatican Radio website.