"The EU-Turkey action plan is our priority," European Council President Donald Tusk said after late-night talks at an EU gathering in Brussels.

The EU has pledged €3bn (£2.3bn; $3.3bn) to Turkey in return for housing refugees on its territory.

More than a million people arrived in the EU in 2015, creating Europe`s worst refugee crisis since World War Two.

On Thursday, about 900 migrants were rescued near the Greek island of Lesbos, the EU border agency Frontex said.

In a separate development at the Brussels summit, talks on reform of the UK`s place in the EU continued into the early hours after London said there was "real hard work to do overnight".

Mr Tusk said although there had been progress, "a lot still remains to be done".

`Clear danger`

Speaking in Brussels well after midnight, Mr Tusk said a "European consensus" on how to tackle the refugee crisis was needed.

"We must do all we can to succeed. This is why we have the intention to organise a special meeting with Turkey at the beginning of March," he said.

Mr Tusk said he would now hold a series of bilateral meetings with EU leaders to further discuss the issue.

He said decisions must ultimately be made by each EU member - but stressed that such moves must be guided by common EU laws.

Migrants aboard a ship on Greece`s island of Lesbos. Photo: 18 February 2016AFP
About 900 migrants were rescued near the Greek island of Lesbos on Thursday
Echoing his words, German Chancellor Angela Merkel said the EU-Turkey action plan "is something we will be concentrating on".

She said the number of migrants trying to reach Europe had dropped in recent months, but warned that there was a "clear danger" of a new influx in the spring because of warmer weather.

Ms Merkel pointed out that Austria also backed the EU-Turkey plan, despite Vienna`s decision on the eve of the summit to impose a daily quota on asylum claims.

Officials in Vienna said that 80 asylum applications would be accepted each day, and a maximum of 3,200 people would be allowed to travel through Austria.

The BBC`s Bethany Bell reports from Austria`s Spielfeld border control centre
Correspondents say there are signs of serious divisions between EU members on the migrant issue.

The Czech Minister for European Affairs, Tomas Prouza, tweeted that "well balanced and direct draft conclusions on #migration being taken apart over the last two hours".

Turkish Prime Minister Ahmet Davutoglu had been expected to take part in the Brussels` summit on Thursday - but he had to cancel his trip due to a deadly bomb attack in Ankara.

Turkey is home to nearly three million refugees, most of them from Syria.

Many of them pay smugglers thousands of dollars to make the crossing to Greece. They then head north, trying to reach Germany and Scandinavia.

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