US forces shot down an Iranian drone 60 miles (100km) north-east of Baghdad last month, the US military says.
A military spokesman said the Unmanned Aerial Vehicle (UAV) was in Iraqi airspace for almost an hour and 10 minutes before it was engaged.
"This was not an accident on the part of the Iranians," the spokesman said, without elaborating. The incident took place on 25 February, he said.
The US has long accused Iran of military interference inside Iraq.
There was no immediate comment from Iran.
The US spokesman said in a statement that pilots "were directed to shoot the UAV down after determining there would be no possibility of collateral damage".
The unmanned Iranian aircraft was believed to be an "Ababil 3", he said.