Pentagon spokesman Colonel Steve Warren said that while there is a "small group" of Shiite fighters at the Taqaddum base, there numbered only in the lower double digits, did not form full units and did not interact with US forces.
Taqaddum is a key area in the fight to retake the city of Ramadi and the Sunni province of Al-Anbar from the Islamic State group.
But the United States is hesitant to see Shiite militias involved in its efforts to battle IS, despite their battle readiness.
Many of the forces are backed by US-rival Iran and the military has not forgotten intense fighting with Shiite groups after the 2003 American invasion of Iraq.
The US and international observers also fret that such militias could spark sectarian fighting during campaigns.
In its annual report on terrorism released Friday, the US said Tehran continues to "sponsor terrorist groups around the world."
"There were Shia militias units on Taqaddum at one point," Warren added. But "one of the conditions for our arrival there was that these units move off Taqaddum airbase".
IS launched a brutal offensive last June that overran large areas north and west of Baghdad.
Iraqi forces have made gains in Diyala and Salaheddin provinces north of Baghdad, but much of the country's west is still in IS hands.
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
