After more than two years of ISIL occupation of Mosul, Iraqi, Kurdish, American and French forces launched a joint offensive to recapture the city on 16 October 2016. The battle for Mosul was considered key in the military intervention against IS. Turkish warplanes participated in the coalition strikes on Mosul, amid the escalating dispute between Baghdad and Ankara about the Turkish presence in Bashiqa. A military offensive to retake the city was the largest deployment of Iraqi forces since the 2003 invasion by U.S. and coalition forces On 9 July 2017, Prime Minister Haider Al-Abadi arrived in preparation to announce the full liberation of Mosul and reclamation of the city after three years of ISIL control. A formal declaration was made on the next day. The battle continued for another couple of weeks in the Old City, however, before Iraqi forces regained full control of Mosul on 21 July 2017.