Iraq and the U.S. are planning a counterattack against ISIS in the Iraqi city of Mosul.

U.S. Central Command (CENTCOM) announced most of the troops involved would be Iraqi but there could the possibility of some American troops on the ground.

ISIS has controlled Mosul, Iraq's second largest city, since June 2014 but now CENTCOM has announced Iraqi forces are planning to retake the city sometime between April and May, reports the AFP.

"The mark on the wall we are still shooting for is the April-May timeframe," the official said, "it becomes problematic if it goes much later (than May)" because of Ramadan and the increasing summer heat.

The planned counterattack will involve between 20,000 to 25,000 troops mostly from five Iraqi brigades. There will also be three Kurdish brigades. They will fight the estimated 1,000 to 2,000 ISIS troops inside the city.

The Iraqi troops will most likely attack from the south as the Kurdish peshmerga will secure the northwest flank of the city, separating the city from the rest of ISIS-controlled land in Syria, reports Reuters.

The Iraqi troops currently being trained by the U.S. will be the ones to take part in the operation. There are 3,200 troops undergoing training in five bases, training will continue once these troops are rotated out.

According to Star and Stripes, the training of troops takes around four to six weeks and the plan will be postponed if the Iraqi troops do not appear ready. However, the Pentagon officials seemed mildly optimistic.

"The shaping for Mosul and the isolation of Mosul is going on now. The preparation for the forces that will participate in Mosul is ongoing right now," said the official.

American troops will most likely not be involved in the fighting, rather helping with logistics, airstrikes, intelligence gathering and surveillance, according to the official. However, there is the risky possibility U.S special operators could be sent in to call in airstrikes.

The officials said in the briefing they were releasing this information ahead of a strike to show the Iraqis' determination.

"They are absolutely committed to this. There are a lot of pieces that have to come together and we want to make sure the conditions are right. But this is their plan. They have bought into it. They are moving forward as if they will execute in the time frame that I just described," the official said, according to Reuters.

However, they could have another plan.

Although Republican legislators like Sens. John McCain and Lindsey Graham are "deeply disturbed" by CENTCOM's revelations, as reported by The Hill, the Pentagon may have different plans.

The Washington Post explains the Pentagon could be attempting to scare the ISIS fighters ahead of the attack to prevent any fighting.

"We want Mosul to look a lot more like the liberation of Paris than Stalingrad or Fallujah," a senior military official told the Washington Post.

It remains uncertain whether ISIS will leave the city before the Iraqi troops attack but, if the plan succeeds, very little blood will be spilled.

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