German Chancellor Angela Merkel has urged European leaders to work together on finding solutions to irregular migration.
She told Germany's parliament the issue could be a defining moment for the EU.
The call comes as leaders meet for an EU summit focused on how to deal with the many undocumented migrants - mainly Africans - who continue to risk their lives to cross the Mediterranean.
Mrs Merkel is under pressure to come up with a deal to prevent new arrivals.
Interior Minister Horst Seehofer, from her Bavarian coalition partner the CSU, has given her until this weekend. Otherwise he has said he will start turning away migrants from the border in his home state.
Mr Seehofer threatened to start blocking migrants at the border if they have already registered in another EU country. Without his party, the CSU, Mrs Merkel would lose her parliamentary majority.
The migrant flows also include refugees fleeing the Syrian war and other conflicts, urgently seeking asylum.
It is not a crisis on the scale of 2015, when thousands were coming ashore daily on the Greek islands. The European Council - the EU's strategic leadership - said the numbers illegally entering the EU have dropped 96 percent since their peak in October 2015.
But this month's tensions over migrant rescue ships barred from entry to Italian ports - most recently the German charity ship Lifeline - have put the issue firmly back in the EU spotlight.
The Lifeline was only allowed to dock in Malta after intense diplomacy among several EU states, who each agreed to take a share of the migrants on board. Malta said that Norway had now also agreed to take some migrants.
The Dublin principle - that asylum seekers should stay in the country where they enter the EU - has broken down. Italy and Greece, who receive the most, are demanding that their neighbours share the burden.