Iran-backed Shia forces in Iraq have grown to 100,000 in the war against Daesh Takfiri militants, says Baghdad-based US military spokesman, Colonel Chris Garver.

In an email to Fox News, Garver said that since the rise of Daesh terrorists inside Iraq more than two years ago, Shia forces have grown to 100,000 fighters.

Garver added that the fighters have been able to grow inside the Popular Mobilization Units.

Iraqi government forces, backed by fighters from allied Popular Mobilization Units, have been pushing the militants out of the country’s territory.

Fox News reported that this is an alarmingly high number and is the first time such a figure has been estimated. The American news channel also reported concerns that the Shia fighters represent an “anti-American force” that would take over once Daesh are defeated.

Many have been critical of the US’ role in Iraq. Last month, an Iraqi parliamentary panel opposed the role of US troops in the liberation of Mosul, in light of the news that the US was planning to send hundreds of additional troops there.

Iraq’s MP Nayef al-Shammari said that "Iraqis have already retaken Tikrit, Fallujah and... Ramadi."

When asked about Shia fighters' involvement in the liberation of Mosul, Garver said, “the government of Iraq is in charge of this war. We're here to support them. So, who they [want in] the campaign is really their decision.” However, he strongly stressed that there is no coordination between the US and Iranians “in any way.”

Iraq is preparing for an offensive into Mosul, the country’s second largest city, which fell into the hands of Daesh in the summer of 2014. The city is the last remaining bastion of Daesh in Iraq as the military and allies have managed to retake key towns and villages from the militants over the past months.

Iraqis managed to recapture the city of Fallujah, west of the capital Baghdad, in late June. The city was a main hub of Daesh militancy in Iraq and its liberation boosted hope for Iraq’s final push toward Mosul.

Defense Minister Khaled al-Obaidi has said that less than 10 percent of the Iraqi territory remains in the hands of Daesh.