Turkish Foreign Minister Mevlut Cavusoglu said over the weekend that Ankara would back out of the agreement with the EU if the bloc did not deliver the promised visa-free travel for Turks in return.
The 28-nation EU depends on Ankara to enforce the deal, which has sharply cut the number of refugees and migrants leaving Turkey for Greece. Grappling with a major financial crisis, Greece struggled to cope with the influx.
"Up to now the agreement is well-kept," Greek migration minister Yiannis Mouzalas said in a transcript of remarks.
"...Of course we are worried, but up to now, the number of people arriving on our islands is not an indication of non- compliance towards whatever has been agreed."
Greece's migration ministry issued what it said were written responses to Bild questions after the German publication quoted Mouzalas as saying the EU needed a 'Plan B' to counter Turkish threats to back out of the accord.