Turkish President Recep Tayyip Erdogan on Wednesday repeated a call on the Kurdish Regional Government to reverse its decision to hold a referendum on independence.
"I hope that they return from this erroneous decision and continue as the Kurdish Regional Government," Erdogan told Bloomberg Editor-in-Chief John Micklethwait during an interview at the Bloomberg Business Forum in New York City.
Erdogan said Turkey would respond with sanctions if next week's referendum went ahead.
Residents in provinces controlled by the KRG are scheduled to vote Sept. 25 on independence from Baghdad.
The oil-rich province of Kirkuk is among the contested areas where the vote is planned.
The Turkish president justified plans to purchase the S-400 anti-aircraft missile system from Russia as his administration's responsibility to protect his country.
"Given that S-400 systems are deployed in neighboring Syria, I should try to get S-400 and even more," he said. "These are measures we take to protect ourselves. There are steps that we need to take with regard to ballistic missiles, as well."
Erdogan said he would have a phone conversation with Russian President Vladimir Putin next Monday and subsequently have dinner with him Thursday in Turkey.
"We will talk about what is happening in Syria," he said.
Regarding the PYD/PKK terror group's activities in northern Syria in cooperation with the U.S. against Daesh, Erdogan said: "I don't understand how a country that believes in democracy cooperates with a terror group to destroy another terror group."