Germany does not do its part in the fight against terror groups constituting a threat to Turkey, Ankara said, blaming Berlin amid recent tensions between the two historic NATO allies. After German national Peter Steudtner was remanded in custody by a Turkish court this week, German Foreign Minister Sigmar Gabriel denounced his detention, and also signaled a shift in Turkish-German ties, saying they "can't go on like before." Ankara said that Steudtner has been remanded in custody as part of an anti-terror investigation, and this move is not against German nationals in general. In addition, Gabriel's demands from the government with regard to Steudtner have also been crticizied by Ankara, saying that it is a judicial process and no one has the right to interfere.Commenting on recent tensions in Turkish-German ties, President Recep Tayyip Erdoğan said Sunday, "Nobody has right to interfere in Turkey's domestic affairs." Steudtner was part of a group of suspects allegedly planning provocative events meant to fuel unrest across Turkey similar to the 2013 Gezi Park protests.Erdoğan said Turkey will do anything possible to counter those who are involved in provocative acts in Turkey and even try to continue these via their diplomatic services.

Regarding Gabriel's remarks on Turkish-German ties, Erdogan said, "We are together in NATO. We're a negotiator state in the EU process. We have been partners for a long time. No step casting a shadow over this partnership should be taken."

Erdogan also complained that many Gülenist Terror Group (FETÖ) members are moving about freely in Germany.

"Their names were already given" to Germany, Erdoğan said, but they have not been extradited, despite the extradition agreement between the two countries. "If you give shelter to terrorists escaping from Turkey to Germany, give them the opportunity to promote terror, welcome them when they escape Turkey even though they were tried in Turkish courts and found guilty, reward them by having them speak in various public meetings, host them at the presidential office, I'm sorry but our stance toward you will not be the same," he said.

Meanwhile, the Turkish and German foreign ministers held a phone call, according to diplomatic sources, who asked not to be named due to restrictions on speaking to the media. The phone call between Mevlüt Çavuşoğlu and Sigmar Gabriel took place Saturday amid recent tensions between Turkey and Germany.

In an open letter published Saturday by Germany's Bild daily, Gabriel said that the government wants to let them know that "the friendship between Germans and Turks is a great treasure." "However difficult the political relations between Germany and Turkey, one thing is clear: You, people of Turkish roots in Germany, belong here with us, whether you have a German passport or not," Gabriel wrote in his open letter.

FETÖ, which organized the defeated coup bid in Turkey last year that killed 250 people, has a large network in Germany, which is home to more than 3 million Turkish immigrants.

Since the defeated coup attempt, nearly 4,000 FETÖ suspects have left to Germany from Turkey and other countries, according to local media reports. Apart from FETÖ, the terrorist PKK also has a large network in Germany and carries out significant propaganda, recruitment and funding activities. The PKK is considered a terror group by the U.S., the EU and Turkey.

While Turkish leaders have slammed German authorities for not showing solidarity in the fight against terrorism, German politicians have criticized Turkey over human rights and press freedom issues.

'Regardless of Germany, Turkey will pursue defense projects'Regardless of whatever decisions Germany may take, Turkey will continue to pursue projects for a self-sufficient military apparatus, a top Turkish defense official said on Saturday.

If, as some media reports claim, Germany halts defense industry projects with Turkey, "maybe this would slow down some projects, but it would not affect the outcome. It would boost our motivation for national and local systems," Ismail Demir, undersecretary for the Turkish defense industry, told Anadolu Agency (AA). Amid tensions with Ankara, German Foreign Minister Sigmar Gabriel said on Thursday that Berlin would not encourage German businesses to invest in Turkey, nor would it provide investment guarantees to such companies. German dailies have also claimed that Berlin would freeze defense projects with Turkey.