VATICAN CITY (CNS) -- Working to turn migrants away from the prospect of peace and security in a new country is "a grave sin," Pope Francis said.

"It needs to be said clearly: There are those who systematically work by all means to drive away migrants, and this, when done knowingly and deliberately, is a grave sin," he said during his general audience Aug. 28.

The pope began his audience in St. Peter's Square by explaining that he would "postpone the usual catechesis" -- he currently is in the middle of a series of talks about the Holy Spirit -- to discuss "the people who -- even at this moment -- are crossing seas and deserts to reach a land where they can live in peace and security."

"Brothers and sisters, we can all agree on one thing: Migrants should not be in those seas and in those lethal deserts," he said. "And, unfortunately, they are there."

But migrants cannot be deterred from those deadly crossings "through more restrictive laws, nor through the militarization of borders, nor through rejections," the pope said. "Instead, we will achieve it by expanding safe and legal avenues for migrants, by facilitating sanctuary for those fleeing wars, violence, persecution and many calamities; we will achieve it by fostering in every way a global governance of migration based on justice, fraternity and solidarity."

Everyone, he added, must join forces "to combat human trafficking" and "stop the criminal traffickers who mercilessly exploit the misery of others."

"What kills migrants is our indifference and that attitude of rejection," he said, and, praising the many "good Samaritans" and organizations working to support migrants, he noted that ordinary people must be involved in alleviating the plight of migration as well.

"We cannot be on the front line, but we are not excluded; there are many ways for one to make their contribution, first of all prayer," the pope said, asking visitors in the square directly: "Do you pray for migrants? For those who come to our lands to save their lives?"

Pope Francis followed his question to the audience with a pregnant pause.

The pope made specific mention of Mediterranea Saving Humans -- an Italian NGO that rescues migrants crossing the Mediterranean Sea -- as a group "on the front line" of the migrant crisis. The group posted a message on social media Aug. 24 saying the pope had blessed the crew of a ship set to sail on a rescue mission in the Mediterranean Sea organized with the migration office of the Italian bishops' conference.

According to the U.N. Refugee Agency, 4,110 people died or went missing while crossing the Mediterranean Sea in 2023.

Referring to the migrant deaths in the Mediterranean, the pope said that "the tragedy is that many, the majority of these deaths, could have been prevented."

Reflecting on the seas and deserts migrants many cross to reach their destinations, Pope Francis noted the biblical significance of such areas as "places of suffering, of fear, of despair, but at the same time they are places of passage to liberation, to redemption, to attaining freedom and the fulfillment of God's promises."

Yet the Mediterranean Sea and the deserts, plains, forests and jungles crossed by migrants in pursuit of a better life have become "migrant cemeteries," the pope said. "And even here these are often not 'natural' deaths, no. At times, they have been taken to the desert and abandoned."

But, Pope Francis said, "to accompany the people on their journey to freedom, God himself crosses the sea and the desert."

"God does not remain at a distance, no. He shares in the migrants' drama, God is there with them, with the migrants," he said. "He suffers with them, with the migrants, he weeps and hopes with them."