"One 1st Infantry Division Soldier was killed and one was wounded in an operation near Duluiya on 21 January at about 2.10am (2310 GMT Thursday)," the military said in a statement on Friday.
The assault on eight locations rounded up 22 people, but 10 were later released, it added.
The death raises US losses to 1362 in Iraq since the March 2003 invasion.
British soldiers wounded
An Iraqi civilian was killed and nine British soldiers were wounded in an attack outside a British army base in southern Iraq, the British military said in a statement on Friday.
The explosion happened outside
the British military near Basra
"At least seven Iraqi civilians were also injured, one of whom was killed," the statement said. The blast occurred on Thursday at the Shaibah Logistic Base, about 10km southwest of Basra.
"A static civilian vehicle parked a short distance from one of the entrances to the base exploded as a UK military convoy passed it. It is not clear whether this was a suicide device or not," the statement said.
"We can confirm that nine soldiers from 2nd Battalion The Princess of Wales's Royal Regiment were injured," the statement said.
Witnesses suggested that the blast was caused by a suicide car bomb but the British military said it could not yet determine whether the dead Iraqi was involved in the blast.