More than 2,000 migrants arrived on Greece's islands on Monday as European Union leaders and Ankara officials held an emergency summit in Brussels aiming to stem the migrant influx from Turkey towards Europe.

Despite a deadly shipwreck in the Aegean Sea on Sunday that claimed the lives of at least 18 people, rubber dinghy boats continued to leave Turkey bound for Greece.

The Greek coastguard brought hundreds of migrants, including many young children, to shore.

According to Greek government figures, 2,293 migrants had arrived early Monday to the country's Aegean Islands, with 987 of those arriving on Lesbos Island alone.

EU leaders voiced guarded optimism before a summit with Turkey on Monday that Ankara was finally ready to act to curb migrants crossing illegally into Europe.

With tens of thousands of migrants stranded in Greece by closing borders, the summit will formally declare the Balkan route from Greece to Germany closed, diplomats said.

Leaders will pledge help to Athens cope with the backlog and seek assurances that Turkey, with NATO naval backup in the Aegean, will stop people smugglers putting migrants to sea.

But EU officials will be careful not to alienate Ankara just as hopes are rising for a solution to the crisis.

Fellow EU leaders, long divided over how to end chaotic movements that have put Europe's Schengen open-border system in jeopardy, will also assure Greek Prime Minister Alexis Tsipras they will help house migrants now stranded in Greece.

Tsipras said the bloc must speed up the process of relocating registered asylum seekers from Greece to other EU countries as promised last September.

EU states have so far taken in only a few hundred of a promised 160,000 people.

An EU endorsement of border closures by Macedonia, Austria and other countries on the route north from Greece will be accompanied by a renewed commitment to revive the relocation plan, diplomats said.

NATO said on Sunday, that a new naval force had approval to operate in Turkish and Greek waters.

That will lend force to a deal with Turkey to take back migrants halted in its waters and those who reach Greek islands but do not qualify for asylum.

Germany has been pushing for direct resettlement of thousands of Syrian refugees from the 2.9 million in Turkey.

But diplomats say that is unlikely to be discussed in detail by other EU leaders until they see flows from Turkey are falling.

Over a weekend that saw at least another 25 people drown in the straits, Turkish police mounted a raid on a beach opposite Lesbos.

Reuters journalists saw them stop some 120 migrants from leaving and arrest at least two from a migrant-smuggling gang.