EU leaders met late into the night Monday over last-minute proposals out of Ankara to take back migrants from Greece in return for a doubling of EU aid and other concessions, but the plan looked unlikely to win immediate approval.
Europe has struggled with an influx that saw more than 1 million migrants and asylum seekers reach its shores last year, with some 135,000 more already since January. Many are fleeing the war in Syria, but economic migrants from Africa and the Middle East have joined their ranks.
To stem the flows, the European Union has sought help from Turkey, which has been the launch pad for most migrants. Last year, Brussels offered 3 billion euros (3.3 billion dollars) to improve the lives of Syrians in Turkey, in return for efforts by Ankara to prevent their onward journey.
"But still the waves of refugees are continuing," Turkish Prime Minister Ahmet Davutoglu said, speaking at NATO on the outskirts of Brussels, while EU leaders mulled plans he had unexpectedly put to them earlier Monday.
Monday's talks were extended into the evening to discuss the new ideas out of Ankara, but EU leaders struggled to find common ground. Maltese Prime Minister Joseph Muscat said a breakthrough looked unlikely Monday, according to his country's EU representation.
Hungarian Prime Minister Viktor Orban vetoed a Turkish request for asylum seekers to be directly resettled from Turkey to EU member states, government spokesman Zoltan Kovacs wrote on Twitter.
Davutoglu said the new proposal sought to "rescue the lives of the refugees, ... to fight against human smugglers, and to have a new era in Turkish-EU relations."
Under the plan, seen by dpa, Turkey would "readmit expeditiously all irregular migrants crossing into the Greek islands from Turkey ... for a temporary period and only for humanitarian purposes."
In return, Turkey demanded that the EU take in Syrian refugees living on Turkish soil, with one asylum seeker to be resettled for each migrant taken back from Greece.
European Parliament President Martin Schulz said this would deal a "blow against traffickers," by convincing people to file for asylum before leaving Turkey.
Davutoglu said that Ankara and Brussels would also seek to "rescue these refugees before they cross [the] Turkish border." He did not provide further details.
The Turkish proposal calls on the EU to approve an additional 3 billion euros for Syrian refugees in Turkey by 2018.
Other demands include lifting EU visa requirements for Turkish citizens before July and progress in Ankara's long-running efforts to join the bloc.
Davutoglu called for "solidarity" before meeting his EU counterparts, noting that Turkey and the bloc need one another. Ankara says it has taken in 2.7 million Syrian refugees at a cost of more than 10 billion dollars.
But Austrian Finance Minister Hans-Joerg Schelling said he was "not prepared" to make more money available until countries including his received more help in shouldering the burdens of the refugee crisis.
The talks with Davutoglu also touched on other issues, notably the Turkish government's recent takeover of opposition media.
Leaders including British Prime Minister David Cameron voiced their concerns during the summit, a Downing Street spokesperson said.
Earlier, Luxembourg Prime Minister Xavier Bettel called for an "honest" exchange with Davutoglu, saying "it cannot be that because of the refugee issue other values that are important for Europe, such as freedom of the media, just get thrown overboard."
EU leaders were due to discuss border restrictions imposed along the Western Balkan migration route from Greece to northern Europe. The move has sparked a humanitarian crisis in Greece, which was already overwhelmed with thousands of stranded migrants.
More than 13,000 people were waiting to cross from Greece into Macedonia, aid agencies estimated early Monday. Local media reported that the border between the two countries was closed, including for freight trains.
Merkel was resisting moves at the summit to declare the Western Balkan route closed, as demanded by countries along the path.
"When it comes to the question of how we get the number of refugees to decrease not just for some, few countries, but for all countries - including Greece - it cannot be about closing something or other," Merkel told journalists.