Relations between Berlin and Ankara have soured recently over a German Parliament resolution labeling the 20th century killing of Armenians as "genocide", Turkey's crackdown on the opposition and civil society following a failed coup last summer, and appearances in Germany by Turkish officials campaigning for constitutional change in an upcoming referendum. But Cavusoglu's remarks on TV 24 channel came only three days before the one-year anniversary of a deal brokered between Brussels and Ankara that would allow for irregular migrants in Greece, the starting point of the trek to northern Europe, to be returned to Turkey in exchange for Syrian refugees hosted on Turkish soil.
"If Turkey really is a state under the rule of law as Mr Erdogan claims, I ask myself how he already knows and can say before the start of a trial that Deniz Yucel is a terrorist and a spy", Gabriel told German magazine Der Spiegel in an interview that will be published on Saturday.
In addition bans on planned rallies by Turkish ministers in Germany to drum up support for Erdogan have also caused anger.
But Turkish ministers and Erdogan have said they need to respond to popular demand for the restoration of capital punishment to deal with the ringleaders of the July 15 coup bid.
He raged: "They are trying to complete the work that they did not finish".
Now, Turkey threatens to rip up the deal and flood Europe with thousands of refugees into the continent each month. "That's because you are the future of Europe".
"There needs to be a strong message sent out that we will be turning back boats from whence they came, that we will not be permitting huge numbers of migrants travelling from Turkey into European Union countries in order to travel through to other richer countries".
In a speech given to supporters in the western Turkish city of Sakarya, President Recep Tayyip Erdogan invoked the medieval religious wars between Christian European forces and Islamic Middle Eastern rulers in the context of present-day escalating tensions between the European Union and Turkey.
"The UK Home Office needs to set out their strategy for how they are going to be dealing with this when it inevitably hits the UK's border. Did you provide support to Turkey in its fight against terrorism?"