Top European officials warned on Monday of the consequences of the potential failure of a deal with Turkey to curb migrant influx and an interruption of EU accession talks with Ankara.
In an interview with Germany's Tagesspiegel, European Commission President Jean-Claude Juncker said it was important to keep the deal with Turkey on track.
According to Juncker, the EU must continue to work with difficult partners like Turkey "not because we like their governments but because we owe it to all those who would suffer if we fail to agree."
He added, however, that the EC would not offer Ankara concessions on the issue of visa-free travel.
Meanwhile the European Commissioner for Migration Affairs Dimitris Avramopoulos told Germany's Die Welt that the EU would be prepared even in the event of a failure of the migrant deal with Turkey. "The deal with Turkey is an important part of our work as regards tackling the refugee crisis but by no means the only part," he said.
The past two years have already seen significant work in this area, he said.