Updated

The European Union is discouraging Iraq's semi-autonomous Kurdish region from holding an independence referendum in September.

EU foreign ministers said in a statement Monday "that unilateral steps must be avoided, and that all open questions must be resolved through consensual positions" based on Iraq's constitution.

The ministers did not explicitly mention the planned Sept. 25 poll, but they did urge all parties in Iraq's northern Kurdish region to "seek common ground" and consider holding regional elections.

The United Nations warned last week that it would not be "engaged in any way or form" in the referendum process. The vote has been criticized by the central government in Baghdad.

Iraq's Kurdish region already enjoys a high degree of autonomy and has its own parliament and armed forces.

Since the 2003 U.S.-led invasion that toppled Saddam Hussein, relations between the region and Baghdad have become strained over a range of issues, including the sharing of oil revenues and control of some areas, such as the oil-rich city of Kirkuk.

Separately, the ministers said the EU is looking to deploy an "advice and assist team" based on an Iraqi request to help reform the war-torn country's security sector.

EU foreign policy chief Federica Mogherini said she hopes the mission can be rapidly put in place "in the coming months."