During an address to the European Parliament he said governments should offer acceptance and assistance to people who flee their own countries.
It was the first visit of a Pontiff to Strasbourg for a quarter of a century after St John Paul II went to speak before the fall of the Berlin Wall.
Francis told MEPs he wanted to bring a message of hope to people who distrusted the parliament and were struggling to cope during the economic crisis.
He said politicians had to find policies that would create jobs for locals and immigrants.
He added: "We cannot allow the Mediterranean to become a vast cemetery."
The Pontiff said the continent needed refreshing, describing it as a "grandmother, no longer fertile and vibrant".
His visit is not without controversy. Many secular politicians have complained that he would only be giving a speech and not willing to join a discussion.
Some Catholics in Strasbourg are also upset that he will only visit for four hours and not meet any locals or visit the city's cathedral.
Director of Christian charity Care for Europe Paul Moynan's in Strasbourg and tells Premier the visit was an important step.
"He represents a huge population of Catholics around the world and carries with him good wishes and encouragement from other Christian denominations," he said.
"I think it's very important that all the politicians and everyone they represent get a chance to hear his voice."
Bishop William Kenney is spokesperson for European affairs at the Bishops Conference and told Premier it was an important visit.
He said: "This is very significant. Other than going to Albania, which doesn't belong to the European Union, the first place he's visited in Europe is the European parliament.
"In other words he is most definitely emphasising the European dimension of our countries.
"In the speech he came back again to peace in Europe."
