An Iraqi government-led offensive to retake the northern Iraqi city of Mosul from Islamic State will start soon, France’s defense minister said on Friday, September 30 after French warplanes took off from the Charles de Gaulle aircraft carrier to strike the militant group, Reuters reports.

The United States on Thursday increased the number of troops it has in Iraq to more than 5,000 as part of a U.S.-led coalition providing air support, training and advice to the Iraqi military, which collapsed in 2014 in the face of Islamic State’s territorial gains and advance towards Baghdad.

Iraqi forces, including Kurdish peshmerga forces and mostly Iranian-backed Shi’ite militias, have retaken around half of that territory over the past two years. Mosul, the largest city under the hardline group’s control anywhere across its self-proclaimed caliphate, is likely to be the biggest battle yet.

“The battle for Mosul has not started yet. (The operations) are the extension of our support for the coalition,” Jean-Yves Le Drian told reporters at a naval shipyard in northwestern France. “There will soon be the main attack.”

The carrier, which arrived in the eastern Mediterranean this week, holds about 1,900 personnel and is accompanied by an attack submarine, several frigates and refueling ships as well as fighter jets and surveillance aircraft.

Eight war planes took off for a mission over Iraq earlier on Friday, according to the defense ministry.

France, the first country to join U.S.-led air strikes in Iraq, has stepped up aerial operations against Islamic State, including in Syria, after several attacks by the group in France.

Paris also has special forces operating in both countries and has provided weapons to Syrian rebel groups, peshmerga and Iraqi forces.