Last month he had warned Trump directly of dire consequences if the term "genocide" is formalized in US law. 

And now, according to The Independent, Erdogan says Turkey could in turn give legal recognition to the mass killing of native Americans by European settlers and American colonists in the latest tit-for-tat move against the Congressional resolution.

"Can we speak about America without mentioning [Native Americans]? It is a shameful moment in US history," Erdogan said in a televised interview this week, raising the threat of a reciprocal measure. Theoretically such Turkish legislation would mean the Turkish government could not associate itself with any event or institution which involved denial of the 'genocide' of native Americans. 

According to The Independent:

Speaking on the pro-government A Haber news channel, he said: "We should oppose [the US] by reciprocating such decisions in parliament. And that is what we will do."

"Can we speak about America without mentioning [Native Americans]? It is a shameful moment in US history."

Thus far Erdogan has remained unwavering in the face of US sanctions threats over Turkey's procurement of Russian S-400 systems, after after the blockage of F-35 jet transfers. 

But the Armenian Genocide issue has long been a sore spot and deeply sensitive issue for the Turkish state. Turkey says many religious minorities died, but disputes that Ottoman troops specifically targeted ethno-religious groups like Armenian, Greek, and Assyrian Christians as a matter of carrying out genocidal polices; instead, it's claimed that famine, disease, and the harshness of war had just as big a part to play as military deaths.