A U.S. military spokesperson in Baghdad said that it is not possible for the Iraqi Security Forces and Peshmerga to completely surround Mosul by Ramadan — clarifying Secretary of Defense Ash Carter's comments on the matter earlier on Wednesday.
Asked whether this goal of encircling Mosul by Ramadan is possible, Colonel Steve Warren said one word: "No."
Warren went on to say that the goal is to sever the main line of communication south of Mosul by Ramadan but it is not possible to completely isolate Mosul in 5 weeks.
Warren also said that the latest estimates are that it will take between 8 to 12 brigades of Iraqi Security forces and Peshmerga, somewhere in the neighborhood of 25,000 troops, to isolate Mosul and that most of those forces have not been trained yet.
A senior defense official later said that the isolation, or encircling, of Mosul is not expected to occur until late 2016. A senior defense official said that Carter "misspoke" and meant the US would like to complete "positioning for the envelopment, not/not the completion of envelopment."
Earlier in the day, Carter put a timeline on the offensive to take back the northern Iraqi city of Mosul telling lawmakers Wednesday that the goal is to completely encircle the ISIS controlled township before the Muslim holy month of Ramadan begins.
Speaking during a Senate Appropriations Committee budget hearing, Carter told lawmakers the coalition will work with Iraqi Security Forces coming from the south and two brigades of Peshmerga forces from the autonomous Kurdish region coming from the north to surround Mosul and wrest it from ISIS control.
"That objective of positioning the forces for the envelopment of Mosul is before Ramadan which is now five weeks away," Carter told lawmakers.
Ramadan begins on June 6 this year.
Carter is set to appear before the Senate Armed Services committee on Thursday to discuss counter-ISIS operations and Middle East strategy.
Militants captured Mosul in June 2014, making the city, which was home to 1 million Iraqis, the largest town in ISIS-controlled territory. Earlier this month President Obama predicted that Mosul would be reclaimed by Iraq by the end of the year.
The U.S. has employed a variety of new tactics in an effort to fight ISIS in Iraq and avoid civilian casualties. For example, earlier this month in Mosul, the U.S. military recently employed an Israeli battlefield tactic: roof knocking.
This technique involves blowing up a bomb above the roof of a building to warn civilians inside to get out, Major General Peter Gersten, the deputy commander for operations and intel in Iraq said during a briefing on Tuesday.
"We went as far as actually to put a Hellfire on top of the building and air burst it so it wouldn't destroy the building, simply knock on the roof to ensure that she and the children were out of the building," he said. "And then we proceeded with our operations," he said, referring to a woman and at least one child who the U.S. observed in the building prior to the airstrike.
Gersten said that after the knock-on-the-roof operation, the U.S. observed the woman leave the building, and that "multiple men literally trampled over her to get out of that building." Then, after the US fired the weapon to take out the building, the woman ran back inside and ultimately was killed.
"So, as much as we tried to do exactly what we wanted to do and minimize civilian casualties, post-weapons release, she actually ran back into the building," he said, adding that it was "very difficult for us to watch" as she ran back inside "within the final seconds of the actual impact."
Gersten could not say exactly when this strike occurred, but Tuesday a defense official said that it took place on April 5 in Mosul.
Gersten said that the target was an ISIS bulk cash storage site and the Emir who lived there. He said that there was roughly $150 million stored in the home and, asked whether the Emir was killed in the strike, he said, "we have not seen the Emir reemerge on the net."