Turkish President Tayyip Erdogan (Source: AFP/VNA)

Flights to northern Iraq have already been suspended and the air space and borders will close soon, Erdogan said. He added that the decision to hold the referendum showed the “perfect ingratitude” of the Kurdish Regional Government in northern Iraq, after years of close commercial and political ties with Turkey. 

Turkey has vowed to take any necessary measures, including political, economic sanctions, and military intervention, to retaliate for the Kurdish independence referendum.