German Economy Minister Sigmar Gabriel attends a news conference in Berlin, Germany, July 13, 2016. REUTERS/Hannibal Hanschke/Files

ROSTOCK, Germany (Reuters) - Germany and the European Union should not be blackmailed by Turkey in talks on visa liberalisation for Turkish nationals, German Vice Chancellor Sigmar Gabriel said on Monday.

“It is up to Turkey if there is or there isn’t visa liberalisation,” Gabriel said during a trip to northern Germany. “Germany and Europe should under no circumstances be blackmailed.”

Gabriel also welcomed a decision by Germany’s highest court to prevent Turkish President Tayyip Erdogan from addressing via video-link a rally in Cologne on Sunday.

Turkish Foreign Minister Mevlut Cavusoglu said in remarks published at the weekend that Ankara would back out of its agreement with the EU to stem the flow of migrants into the bloc if the EU doesn’t deliver visa-free travel for Turks.

Visa-free access to the EU - the main reward for Ankara’s role 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.