By Phil Stewart
KUWAIT CITY, Dec 8 (Reuters) - U.S. allies have committed to send about 1,500 forces to Iraq to help train and advise Iraqi and Kurdish soldiers battling the Islamic State, which increasingly appears on the defensive, the top U.S. commander guiding the coalition effort said on Monday.
Lieutenant General James Terry, commander of Operation Inherent Resolve targetting the militants in Iraq and Syria, said the forces would come on top of the up to 3,100 troops U.S. President Barack Obama has authorized to deploy to Iraq.
The allies' commitments were made during a conference among coalition members on Dec. 2-3.
"When you start now to balance the different capabilities out across the coalition, I think we're doing pretty well in terms of boots on the ground," Terry told reporters traveling with Defense Secretary Chuck Hagel in Kuwait.
Since Islamic State's June offensive, the Sunni militants have had little success breaking beyond the solidly Sunni Muslim provinces of Anbar in the west and Salahuddin north of Baghdad, as well as the strongly Sunni province of Nineveh, home to the city of Mosul which the Islamists overran in June.
At the same time, the Iraqi and Kurdish forces have been able to tout important gains, including securing Mosul dam.
Although the Islamic State still conducted limited attacks, the group appeared broadly "on the defense, trying to hold what they have gained," Terry said.
"When you look at some places out in Anbar, it's a little bit stalemated out there. And we've got some work to do. And I think it's do-able," Terry said.
Hagel, speaking to reporters after the Pentagon chief visited U.S. troops in Kuwait, said he wasn't ready to say the Islamic State was "on the ropes." But he noted recent gains had given Iraqi and Kurdish forces new momentum.
Terry declined to say which countries would contribute the roughly 1,500 troops -- the final number was still being determined -- but added most would be involved with training.
He said the troops would represent a broad mix from a anti-Islamic State coalition that, on the military side, now included nearly 40 countries. The U.S.-led coalition has also carried out air strikes in Iraq since August.
Asked about Obama's critics in Washington who say more U.S. forces are needed, Terry said: "I'm comfortable with the boots on the ground that I have right now." (editing by Ralph Boulton)