The president of Iraq's semi-autonomous Kurdistan Regional Government Masoud Barzani announced on Twitter in June that the northern territory would hold an independence referendum on September 25.

The referendum on whether to secede from Iraq is planned to be held in the three governorates that make up the Kurdish region and in the areas that are disputed by the Kurdish and Iraqi governments but are currently under Kurdish military control.

The disputed areas include the key oil-rich province of Kirkuk.

Politically, the KRG already functions as an independent nation-state with its own parliament, armed forces (known as the Peshmerga) and foreign policy within a federation with the rest of Iraq. But economically, the KRG is still dependent on the central government as a result of a revenue-sharing system for oil wealth.

The Central government of Iraq and the country neighboring including Iran and Turkey have declared their opposition with the idea of referendum. Even the KRG allies including the United States and other western nations have opposed to referendum.

US Secretary of State Rex Tillerson formally asked president of the autonomous region to postpone the referendum.