The battle to recapture Mosul from ISIS could take two months, a Peshmerga military commander told CNN on the second day of the long-awaited offensive to liberate Iraq’s second city.

“My expectation is two months for the fight inside Mosul, but weather is one of the factors that can delay the process,” Sirwan Barzani, a Peshmerga brigadier general, said Tuesday.

He said it would likely take two weeks for the advancing forces to enter the city. But he added that Iraq’s leaders have said that only Iraqi government troops and national police officers will be allowed to do so, amid fears of sectarian retribution.

A diverse 94,000-member coalition comprised of Iraqi security forces, Kurdish Peshmerga allies and thousands of irregulars from various minorities are involved in the operation to free Mosul from more than two years of ISIS rule.