AlHijjah 08, 1436, September 22, 2015, SPA -- Belgrade called on the European Union to respond Tuesday to its member state Croatia's closure of its borders with Serbia, threatening "countermeasures" as the migration crisis winds up diplomatic tensions in the Balkans, dpa reported. "We're waiting for the EU to react until 2 pm (1200 GMT) and then Serbia will react, calmly, without violating rules," Prime Minister Aleksandar Vucic said Tuesday. Serbia "will demonstrate that Croatia cannot without consequence bully and humiliate Serbia, destroy Serbia's economy," he said, describing the closure of border crossings a "scandal of incredible proportions."