BRUSSELS (AP) — 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 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 EU members have been slow in offering money for the migrant crisis overall, and divided over how much to help migrants and how much to help Turkey.

Turkey hosts more refugees than any other country in the world, more than 2 million. Hundreds of thousands are housed in refugee camps but many more are left to fend for themselves, leading some people to try their luck on the arduous journey to Europe, which has seen some 600,000 new arrivals this year.

EU President Donald Tusk expressed "cautious optimism" about securing an agreement with Turkey on what he called "a demanding and difficult issue."

"An agreement with Turkey makes sense only if it effectively contains the flow of refugees," he told reporters early Friday.

The plan would see Turkey improve its asylum and documentation procedures and beef up border security. A draft was presented to Turkish President Recep Tayyip Erdogan last week during a visit to Brussels but has yet to be officially accepted by Turkey.

Turkish officials have not publicly released details of their demands.

After years of membership talks where the EU had the upper hand, now the EU is in a position of needing Turkey's help to ease the refugee crisis.

But EU leaders are concerned about authoritarian moves by Turkish President Recep Tayyip Erdogan toward the Kurdish minority and the media and justice system. Erdogan's government has been pushing for a long time for looser visa rules, and that would be a vote-getter for his party in Nov. 1 elections

German Chancellor Angela Merkel said she is going to Turkey on Sunday to see if the promises made are feasible. She noted that Turkey had spent billions to take in Syrian refugees.

French President Francois Hollande said he "insisted that if there is a liberalization of visas with Turkey ... it should be on extremely specific, controlled terms."