"Submission of German mainstream politics to populism and otherizing would only fuel discrimination and racism,” Turkish spokesperson Ibrahim Kalin wrote on his official Twitter account on Monday.
Discussions regarding Turkey’s ascension into the European Union took center stage during the debate.
Schulz called for a tougher line against Turkey, suggesting that they immediately stop Ankara’s EU membership talks and freeze $4.67 billion in pre-ascension funds.
"If I become the Chancellor, I will cancel Turkey’s EU membership talks,” he said.
Merkel of the Christian Democratic Union (CDU) criticized the rule of Turkish President Recep Tayyip Erdogan, saying “Turkey is departing from all democratic practices at breakneck speed.”
“It is clear that Turkey should not become a member of the European Union,” she added.
Turkey’s chief negotiator for its EU bid, Omer Celik, criticized the candidates for their “careless” tone.
"We do not accept these disrespectful messages against Turkey," he wrote in a tweet.
Relations have become increasingly strained between the two NATO allies in the wake of the failed coup attempt in Turkey last year.
Chancellor Merkel said on Saturday that Germany may have to “rethink” further relations with Ankara following the arrests of two more German citizens who were detained in Turkey on Thursday for what Berlin says were “political reasons,” bringing the total number of German nationals detained in Turkey for the same reasons to 12.
The Turkish ministry released a statement on Monday criticizing German politicians for anti-Turkish rhetoric.
"We want to remind the politicians, who were running behind us during the refugee crisis to save the EU from a great chaos, that not leaving relations with Turkey to the monopoly of populism bears great importance not only for the future of our bilateral relations but also for their political responsibility towards their citizens, including Turkish-origin ones," the statement read.
Ankara became angry earlier this year when Berlin banned Turkish politicians from campaigning in Germany ahead of Turkey's constitutional referendum, citing security concerns. Erdogan responded to the ban by accusing German politicians of “Nazi-like” tactics.
Disputes between Berlin and Ankara prompted Germany to move their military aircraft and roughly 250 troops from Turkey’s Incirlik airbase to Jordan in July. These troops are participating in the US-led coalition’s fight against ISIS in Iraq and Syria.
In July, the German government urged citizens traveling to Turkey to exercise caution, but refrained from issuing a formal travel warning at the time.
