But both Italy and Malta, who have refused port access to the rescue vessels, on Sunday reiterated their positions.
“Forty-nine migrants rescued in the Mediterranean by two NGO ships have been on board for several days now, waiting to be able to disembark,” Francis told thousands of people gathered in St. Peter's Square in Rome, following the Epiphany Mass.
“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 migrants stranded at sea for more than two weeks.
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 Italian Sunday paper Il Messaggero. “That's the line and it will not change.”
He repeated his stance several times this week, after the maoyr of Naples defied Salvini to offer the migrants a safe port in the city.
While not quite as categorical, Maltese Prime Minister Joseph Muscat said Sunday he feared setting a “precedent” and that if he did as Salvini wanted, “the bullies would have won.”
“This is an issue that might set a precedent and we should be vigilant about it,” Muscat 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.”
Relations between Italy and Malta have been strained since Salvini's decision to close Italian ports to the migrants, accusing the rights groups who rescue them of running a migrant “taxi service.”
NGOs said last week that the crisis had reached a “new low” and said politicians were being “pathetic.”
There are 17 people on board the German NGO vessel Sea-Eye, with another 32 on the Sea-Watch. Among them are a one-year-old baby and two children aged six and seven.
Some on board Sea Watch are being treated for dehydration caused by seasickness.
They are “all crammed into a small room and literally vomit on each other”, said Sea Watch spokeswoman Giorgia Linardi, who fears some of the passengers will self-harm.
“The situation is becoming more unstable every day, the level of stress is rising,” added Franck Doerner, a doctor on board, via a video message.
Salvini has called on Malta to assume its responsibilities and take in the rescue boats, arguing they are the closest.
Muscat said that Malta's own naval vessels had in recent days rescued 250 migrants, 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 migrants if their EU partners do the same.
But the bloc's long-running deadlock over sharing responsibility for migrants has yet to be resolved.