Amsterdam - Top EU officials on Saturday reminded Turkey of its international obligations to keep its frontiers open to refugees as thousands fleeing a new government offensive in Syria remained camped out
Up to 20 000 Syrians may be stranded on the border, officials say, trying to get into Turkey which already hosts more than two million refugees from the bloody conflict.
"The Geneva convention is still valid that states that you have to take in refugees," EU Enlargement and Regional Policy Commissioner Johannes Hahn said as he went into talks on the migrant crisis with EU foreign ministers and their counterparts from countries seeking EU membership, including Turkey.
An EU diplomatic source said that the foreign ministers, meeting informally in Amsterdam, would take the opportunity to voice their concerns over the fate of the refugees fleeing the government offensive against rebel forces in Aleppo, Syria's second largest city.
Luxembourg Foreign Minister Jean Asselborn said "everyone has seen the pictures from Aleppo, the tens of thousands of people who are fleeing... fleeing for their lives.
"We face the very real prospect that there will be another huge influx of refugees (into Europe)... that is the result of the indiscriminate bombing around Aleppo," Asselborn said as he went into the meeting.
Turkish Prime Minister Ahmet Davutoglu told a Syria donors conference in London on Thursday that Ankara would allow the latest refugees into the country.
More than a million migrants landed in the 28-nation European Union last year, most of them crossing into Greece from Turkey and then making their way through the Balkans to Germany and other northern member states.
Such numbers have put huge strains on the bloc and the Schengen passport-free zone, with several countries - among them Germany, Austria, Hungary, Sweden - re-introducing border controls while Brussels struggles to find a comprehensive solution.
The EU in November thrashed out a deal with Turkey, offering €3bn to help care for the refugees on its soil and speeding up long-stalled accession talks in return for Ankara's help in curbing the migrant flows.