But both Italy and Malta, who have refused port access to the rescue ships, on Sunday reiterated their positions.
"Forty-nine migrants rescued in the Mediterranean by two NGO ships have been onboard for several days now, waiting to be able to disembark," Francis told thousands of people gathered in Saint Peter's square in Rome.
"I address a pressing appeal to European leaders that they show some concrete solidarity with respect to these people."
The European Commission also urged EU member states to admit them earlier this week as concern grows over their plight, with some of the refugees stranded at sea for more than two weeks, Presstv reported.
This is not the first time the Argentinian pope, himself descended from Italian immigrants, has appealed to European leaders to open their borders.
But there was no sign of Italy changing its policy.
"In Italy, no more people are arriving," far-right Interior Minister Matteo Salvini told the Sunday paper Il Messaggero. "That's the line and it will not change."
And he rammed the message home on Twitter, saying "Italy's ports are and will stay closed."
While not quite as categorical, Maltese Prime Minister Joseph Muscat also set out his reservations on Sunday.
"This is an issue that might set a precedent and we should be vigilant about it," he told Malta's Radio One station.
"It is easy to play the Christmas Saint with everyone, but then come January, February and the summer period we would be told to do the same."
If Malta let in refugees from the two rescue ships, "the bullies would have won", he added.
"That is why we are stressing that we do not want this case to set a precedent."
The small island state of Malta, which has a population of just 450,000, sits in the middle of the Mediterranean, not far from the Libyan coast.
Relations between Italy and Malta have been strained since Salvini's decision to close Italian ports to the refugees, accusing the rights groups who rescue them of running a refugee "taxi service".
Salvini has called on Malta to assume its responsibilities and take in the rescue boats, arguing that they are the closest.
Muscat said that Malta's own naval vessels had in recent days rescued 250 refugees, with the government saying some of them were pulled to safety closer to Italian waters.
The Netherlands and Germany have already offered to take some of the refugees if their EU partners do the same.
But the European Union's long-running deadlock over sharing responsibility for refugees has yet to be resolved.
There are 17 people on board the German NGO Sea-Eye vessel, with another 32 on the Sea-Watch. Among them are a one-year-old baby and two children aged six and seven.