Turkey’s parliament voted on Saturday to extend by a year a mandate authorising the deployment of Turkish troops in Iraq and Syria, two days before a planned independence referendum in northern Iraq’s Kurdish region.

Turkey said earlier it would take security, political and economic steps in response to the referendum, which President Tayyip Erdogan’s spokesman said was a “terrible mistake that will trigger new crises in the region”.

Erdogan has increased deployment of troops into one of Syria’s northern provinces dominated by a militant group. The move added to Turkey’s military involvement in the conflict and its co-operation with Russia, according to two Turkish officials.

Troops with artillery used to set up temporary bases started crossing into a buffer zone on the border between Turkey and Syria this week, the ‘Financial Times’ cited one official.

Increasing deployment is part of Ankara’s efforts to enforce a de-escalation agreement in Idlib, a northern province not under regime control, that was part of a deal brokered between Turkey, Russia and Iran.