"We know very well who's who. Both are the same," Erdoğan told a press conference at Istanbul's Ataturk Airport before starting a two-day Gulf tour in Saudi Arabia.
"What really matters isn't changing the name plate, but what is inside," he added.
Saying that Turkey gives no credit to the terrorist PKK/PYD changing its name to the Syrian Democratic Forces, he said, "Friends don't deceive each other," referring to the U.S.
Last Friday, speaking at a security forum in Colorado, Gen. Raymond Thomas, the head of the U.S. Army's Special Forces, said that the PKK/PYD had rebranded itself the Syrian Democratic Forces to give it a voice in Syria talks and to assuage Ankara.
The U.S. has supported the PKK/PYD along with several other Arab militia groups under the umbrella of the SDF, long vexing Ankara.
The U.S. views the SDF as a "reliable partner" in its fight against Daesh and continues to provide it with arms and equipment against strong objections by Turkey, which views the PKK/PYD as the Syrian offshoot of the PKK terror group.
The PKK has waged a terror campaign against Turkey for more than 30 years that has led to the deaths of more than 40,000 people. It is a designated terror group in Turkey, the U.S., and EU.
TURKEY AND GERMANY
Also commenting on recent tensions in Turkish-German ties, Erdoğan said, "Nobody has right to interfere in Turkey's domestic affairs."
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".
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.
On Gabriel's remarks on Turkish-German ties, Erdoğan 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".
Erdoğan also complained that many Fetullah Terrorist Organization (FETO) 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.
FETO, which organized the defeated coup bid in Turkey last year that martyred 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 FETO suspects have come to Germany from Turkey and other countries, according to local media reports.
Apart from FETO, the terrorist PKK also has a large network in Germany and carries out significant propaganda, recruitment, and funding activities.
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.
