"I don't want to talk about the worst case scenario - talks with the EU are continuing but it's clear that we either apply all treaties at the same time or we put them all aside,"  he told Bild newspaper's Monday edition when asked whether hundreds of thousands of refugees in Turkey would head to Europe if the EU did not grant Turks visa freedom from October, Reuters reported.

Visa-free access to the EU - the main reward for Ankara's collaboration in choking off an influx of migrants into Europe - has been subject to delays due to a dispute over Turkish anti-terrorism legislation and Ankara's crackdown after a failed coup.