Turkish and EU leaders have gathered in Brussels for an emergency summit on tackling Europe's worst refugee crisis since the Second World War.
The EU aims to stem the flow of migrants and plans to declare the route north through the Balkans closed.
It will press Turkey to take back economic migrants and has pledged to give Ankara $3.3 billion, BBC reported.
Last year, more than a million people, mostly from Syria, Iraq and Afghanistan, entered the EU illegally by boat, mainly going from Turkey to Greece.
Many migrants leave Greece in a bid to reach northern Europe, but eight countries have introduced temporary border controls.
Some 13,000 migrants are currently stranded in northern Greece, after Macedonia, backed by Croatia, Hungary and Slovenia, closed its border to all but a trickle of migrants.
The human cost of the migrant crisis was brought home again on Sunday when a boat capsized off Turkey drowning 25 people.
The EU states remain divided over their response to the crisis with strains showing this year even in Germany and Sweden, seen as the countries most open to refugees.
The summit will be in two parts, the first involving Turkey while in the afternoon British Prime Minister David Cameron will join other EU leaders in seeking out a common approach to the crisis.
The EU is expected to ask Turkey to take back thousands of migrants who do not qualify for asylum. In return, the EU will discuss plans to resettle in Europe some refugees already in Turkey.
Last week, European Council President Donald Tusk said he had been told by Turkish President Recep Tayyip Erdogan that his country was ready to take back all migrants apprehended in Turkish waters.
A draft summit communique declared that the route for migrants through the Western Balkans will close. The draft also pledges that the EU will "stand by Greece in this difficult moment and will do its utmost to help manage the situation".
Greece said on Monday that it would meet its pledge on accommodation for refugees, with a capacity of 37,400 by March 15.
The EU last October said it would relocate 160,000 asylum seekers, mainly from Greece and Italy, but there was strong opposition among some members and fewer than 700 migrants have moved.
The future of the Schengen agreement -- which allows passport-free travel in a 26-nation zone -- will also be on the agenda.
