Merkel, Hollande call for unified response to crisis

A new wave of migrants began entering the European Union from Serbia on Monday as the leaders of France and Germany called for a unified response to the continent's biggest migrant crisis since World War II.

The EU has been struggling to cope with the unprecedented arrivals - from the thousands landing on the shores of Greece and Italy to the hundreds risking their lives to climb onto trucks to travel from France to Britain.

The crisis also threatens to hijack a summit in Vienna of leaders from the western Balkans region.