Under the accord, migrants and refugees who cross the Aegean Sea illegally are sent back to Turkey.
"The current system is not sustainable," the European Commission's First Vice-President Frans Timmermans said
The initiative comes after voters punished Chancellor Angela Merkel's conservatives in regional elections earlier this month
But the leaders warned that a Herculean task lay ahead to implement the accord.
"Austria's behavior is hurting our neighborly relations. We cannot and should not deal with each other this way"
More than 680,000 migrants and refugees have crossed to Europe by sea so far this year, fleeing war and poverty...
Germany is struggling to cope with an influx of about 10,000 migrants a day and expects at least a total...
The summit's aim was to agree "common operational conclusions which could be immediately implemented"
For the time being, the thousands of life vests and boats are deposited at a dump further north.
Border crossings have been fitted with gates of steel and concrete.