Turkey turned up the volume of its opposition to a planned referendum on Kurdish independence in Kurdish-controlled northern Iraq today, warning the move could lead to civil conflict.

Comments from Turkish Foreign Minister Mevlut Cavusoglu were among the strongest admonishments from Turkey to date as the Kurdistan Regional Government (KRG) presses ahead with plans for the plebiscite, which is due to be held on Sept. 25. “In that country, which has been through so many problems, a referendum on independence can make the situation even worse. … God forbid, it could even bring civil war,” Cavusoglu said.

A presidential spokesman joined the chorus of objections, saying Turkey would not recognize an independent Kurdish state. Ibrahim Kalin told the private radio station Best FM, “The fundamental reason that we are opposed to this referendum is Iraq’s territorial and political integrity.” Kalin assured listeners that there was “no question of a negative approach to Iraq’s Kurds or to Syria’s Kurds or other Kurds in the region.” Turkey wishes to maintain its friendly ties with the KRG. But when the Iraqi Kurds “unilaterally declare 'we are independent,' who is going to recognize [them]?” Kalin asked. “Baghdad, Turkey, Iran, the neighboring countries — none of these will.”

The statements came amid unconfirmed reports that Turkish President Recep Tayyip Erdogan had invited Massoud Barzani, the president of Iraqi Kurdistan, to Turkey presumably to persuade him to postpone the referendum. Barzani has yet to respond to the invitation said to be extended last month.