The Pope thanked Italy, which has borne the brunt of the rescue efforts, and urged a "broader involvement".
Some 10,000 migrants have been rescued in the past week by Italy's coastguard, but 400 were feared drowned on Monday.
Last year, a record 170,000 people made the crossing to Italy.
Most were fleeing poverty and conflict in Africa and the Middle East.
Earlier this week, an EU spokeswoman said there was no "silver bullet" for the situation.
The Pope was speaking at his first official meeting with Italy's new president, Sergio Mattarella.
He thanked Italy for welcoming migrants seeking refuge at the risk of their lives, but added that it was "evident that the proportions of the phenomenon demand much greater involvement".
"We must not tire in our attempts to solicit a more extensive response at the European and international level," he said.
Mr Mattarella reiterated Italy's call on the European Union for a "decisive intervention to stop this continuous loss of human life in the Mediterranean".
He added: "These broken lives compromise the dignity of the international community and we are in danger of losing our humanity."
Another tranche of 450 migrants arrived in the Sicilian port of Messina on Saturday on an Italian naval vessel. A number of Sicilian towns say they cannot cope with the numbers.
The Italian navy had set up a search and rescue mission called Mare Nostrum in 2013 but it was abandoned in November last year after some EU members said they could not afford it and amid concerns it was encouraging more migrants.
The EU now runs a border control operation called Triton, which only operates close to Europe's coast and has fewer ships. Italian Foreign Minister Paolo Gentiloni says it is underfunded and inadequate.
But the European Commission's migration spokeswoman Natasha Bertaud told the BBC: "We don't have a silver bullet that will make it [the situation] go away."
More than 500 people have died in the first three month of 2015, in addition to the 400 feared drowned when a migrant boat capsized off Libya on Monday.
Since the fall of Muammar Gaddafi in 2011, Libya has been without a stable government allowing trafficking networks to thrive.
Pope Francis has called on Europe and the international community to do more to tackle the rising number of migrants making desperate and often deadly journeys across the Mediterranean.