By Robin Emmott BRUSSELS (Reuters) - Europe's chief executive Jean-Claude Juncker will on Sunday meet with leaders from central and eastern Europe to push for a coordinated response to the influx of refugees before winter sets in. The mini-summit, which EU diplomats said was sought by German Chancellor Angela Merkel, is the latest in a series of top-level EU meetings that have so far failed to settle on a common approach on how to deal with the thousands of migrants streaming into the EU every day. Juncker, who heads the European Commission, has called leaders of Austria, Bulgaria, Croatia, Macedonia, Germany, Greece, Hungary, Romania, Serbia and Slovenia, plus refugee organisations involved, to attend the meeting in Brussels.