AMSTERDAM (AP) — European Union nations anxious to stem the flow of asylum-seekers coming through the Balkans are increasingly considering sending more help to non-member Macedonia as a better way to protect European borders instead of relying on EU member Greece. With Athens unable to halt the tens of thousands of people making the sea crossing from Turkey, EU nations fear that Europe's Schengen border-free travel zone could collapse, taking with it one of the cornerstones on which the 28-nation bloc is built. Because of the relentless influx of people, several EU members have re-imposed border crossings to manage the flow into their nations better. The EU also called on Turkey to open its borders to thousands of Syrians fleeing fierce government offensives and intense Russian airstrikes and said it is providing aid to Ankara for that purpose.