It said on Thursday in an announcement that Staff Sergeant Alberto B Martinez, 37, a supply specialist with the Headquarters and Headquarters Company of the 42nd Infantry Division, was charged on Wednesday in connection with the 7 June deaths of the two officers at Forward Operating Base Danger, near Tikrit.
The 42nd Infantry Division is a New York-based National Guard unit.
"Martinez is charged with violation of Article 118 (Murder) with two specifications of premeditated murder," said a statement issued by the Multinational Task Force in Iraq.
The officers who died were Captain Phillip T Esposito, 30, of Suffern, New York, and 1st Lieutenant Louis E Allen, 34, of Milford, Pennsylvania.
They were also assigned to the 42nd Infantry Division, New York Army National Guard. Esposito was company commander and Allen served as a company operations officer.
The statement said Esposito and Allen died "in what was initially thought to be an indirect fire attack".
An indirect fire attack involves enemy artillery or mortar rounds fired from a location some distance away.
"The initial investigation by responders and military police indicated that a mortar round struck the window on the side of the building where Esposito and Allen were located at the time.
Tikrit, 130km north of Baghdad,
is Saddam Hussein's hometown
Upon further examination of the scene by explosive ordnance personnel, it was determined the blast pattern was inconsistent with a mortar attack," the statement said.
It added that "Martinez is currently in pre-trial confinement at a military confinement facility in Kuwait".
US military officials declined to comment further.
The 42nd Infantry Division took over from the 1st Infantry Division in January and is responsible for a vast section of northern and central Iraq.