European Union leaders are offering Turkey aid, easier access to EU visas and sped-up membership talks in hopes of stemming an unprecedented flow of refugees. Now comes the hard part: persuading Turkey to sign on, and raising billions to make it work.

EU leaders meeting for a summit in Brussels late Thursday agreed to give "political support" for an action plan for Turkey to help it manage its own refugee emergency. But details proved elusive and discussions in Ankara will continue in coming days.

Diplomats said the package could involve as much as 3 billion euros in aid. But money for the migrant crisis has been slow in coming.

EU President Donald Tusk said "an agreement with Turkey makes sense only if it effectively contains the flow of refugees."