Groups of refugees and migrants are heading towards the EU after Turkey said it would not abide by a deal to stop them reaching Europe.
Turkey's communications chief said the country had not received enough support in hosting millions of Syrian refugees.
Its decision followed a deadly attack on Turkish troops by Syrian government forces in northern Syria.
The incident sparked fears of a major escalation involving Turkey and Syria's military ally, Russia.
Greece and Bulgaria - which border Turkey - have sent reinforcements to prevent people entering.
