BRUSSELS — Turkey’s president derided Europe on Friday for not taking in more refugees — a dose of cold water for a European Union plan to give new aid and concessions to Ankara in exchange for stemming the unprecedented flow of people across borders.

EU leaders meeting at a summit in Brussels into the early hours of Friday agreed to give “political support” for an action plan for Turkey to help it manage its refugee emergency, including easier access to EU visas for Turkish citizens and sped-up EU membership talks. The hard part, though, is persuading Turkey to sign on, and raising money to make it work.