Identity of service member and exact location of incident remains unknown.
General says U.S.-trained forces retake town, where ISIS militants unleashed at least nine suicide truck bombs.
U.S.-trained elite forces are seen as far more capable than the mainstream squads that crumbled as Islamic State advanced in 2014, and have played a central role in liberating cities and towns over the past year.
Up to 6,000 ISIS fighters remain in the Iraqi city, Lt. Gen. Talib Shaghati says, as a wide-scale operation to retake Mosul enters its third day.
U.S. forces confirm the presence of sulfur mustard agent on ISIS munition fragments, but say the group's technical ability to develop such weapons is limited.
U.S. president says Islamic State will be defeated in Iraqi city, but expects tough fight.
For over two years, the U.S. president maintains that ISIS can be defeated without American ground troops. But critics say his policy has allowed ISIS to expand its international reach and influence.
Though Kurdish peshmerga push frontline with ISIS back 8 kilometers, their hold appears fragile, retaken villages mostly abandoned. Still unclear how long before forces reach Mosul itself.
Combat footage has begun emerging from local media outlets as Iraq, Kurdish and other coalition forces begin assault on Mosul.
The push to liberate Mosul will be the largest military operation in Iraq since American troops left in 2011 and, if successful, the biggest blow yet to the Islamic State.