The Iraqi air force is to help Kurdish military forces fight Sunni militants in the north of the country.
A statement from Lt Gen Qassim Atta said the air force will provide aerial support to the Kurdish armed forces.
The move is significant because relations between the Kurds and the government have been tense.
Iraq is facing its worst crisis since the 2006 civil war after the Islamic State group captured large areas of land in the country's west and north - including Mosul, Iraq's second-largest city, which fell to the militants in June.
Kurdish fighters are struggling to blunt a new militant offensive that has captured the towns of Sinjar and Zumar and sent tens of thousands fleeing.
The United Nations said last month that more than 500,000 people have been displaced by the violence since June, bringing the total this year to 1.4 million, including more than 230,000 Syrian refugees.
The group drove ethnic and religious minorities out of Mosul and attacked mosques and shrines, claiming they contradicted strict Islamic teachings.
Kurdish forces, known as the peshmerga, have been battling with the militants for control of several towns stretching between the province of Nineveh and the Kurdish Iraqi province of Dahuk.