Sigmar Gabriel said on Thursday that Germany would talk to EU partners about Turkey's aspirations to join the bloc and made clear Berlin could no longer guarantee German corporate exports to the country under the government's Hermes loan program. In 2016 alone, the German government guaranteed 20.6 billion euros ($23.7 billion) worth of exports to the country.
In addition, the German Foreign Minister warned its citizens to be more careful in traveling to Turkey, citing recent detentions of people there, and Ankara's refusal to grant consular access in some cases, in violation of international law.
Turkey's billion dollar tourist industry has already been hit hard recently. Last year, the number of foreign visitors fell to 25.4 million, the lowest in nine years. Bookings from Germany still account for around 15 percent of Turkey's tourists - if they stay away it could be disastrous.
Moreover, Gabriel said he could not envisage talks on expanding the European customs union to include Turkey.
"We need our policies towards Turkey to go in a new direction ... we can't continue as we have done until now. We need to be clearer than we have been until now so those responsible in Ankara understand that such policies are not without consequences," Gabriel told reporters.
The measures against Turkey come in response to the detention of a German human rights activist, and signal a more confrontational stance to the country after an escalation of tensions.
The Bosporus connection - German firms blacklisted
Part of Ankara's anti-German campaign is also a list of 68 companies and individuals in Germany who allegedly have ties with Fethullah Gulen, an enemy of President Recep Tayyip Erdogan.
Turkey blames Gulen and his followers for the failed military coup a year ago, in which over 250 civilians lost their lives in the violence. The movement is banned and branded as a terrorist faction by the state.
The existence of the list was first reported by the German weekly Die Zeit and confirmed on Thursday by a spokeswoman of German chemical giant BASF, which is one of the companies named as a backer of terrorism.
"The German Federal Criminal Office (BKA) has informed us that BASF is named in the list," Ursula von Steffen said in an emailed statement to DW, adding that the company would not comment on the allegations at this time.
BASF has been active in Turkey since the 1880s and today employs 800 people there.
The list which has not been publically released, was forwarded to German investigators several weeks ago, and also names well-known multinationals like premium carmaker Daimler, but includes a Turkish fast food restaurant and a late-night food store, too.
Terrorism purge shifts to Germany
Earlier this month, Erdogan told Die Zeit that his officials sent 4,500 files on alleged Gulen sympathizers to Germany and demanded that they be extradited to Turkey.
"You need to deliver these terrorists to Turkey," he said. "As long as you don't, Turkey will perceive Germany as a country which is protecting terrorists."
German officials view the list from Ankara as "absurd" and "ridiculous." The BKA has requested additional information from their Turkish colleagues, but has received no reply so far, Die Zeit reports.
Germany has been locked in a long-running diplomatic row with Turkey, with Berlin slamming the purges by Erdogan's administration and accusing the Turkish government of using violence to silence its political opponents. Earlier on Wednesday, Germany summoned the Turkish ambassador in Berlin to protest the arrest of several human rights activists, including German citizen Peter Steudtner.
A worse future?
Turkey's economic growth this year is expected to fall slightly short of the government's forecast, according to a new Reuters poll, suggesting not all investor concerns following an April referendum giving President Erdogan sweeping new powers have eased.
While growth forecasts are better than they were three months ago - alongside a rising stock market and a more stable lira - projected growth rates are still well below half the expected inflation rate, suggesting not all is well.
uhe/tr (Reuters, dpa, AFP)