The investigation results will be announced during a conference call with journalists on Tuesday.
"Brig. Gen. Richard 'Tex' Coe, the lead investigating officer, will present the findings and recommendations," the release stated on Monday.
Speaking with Serbia's Politika newspaper earlier this month, Syrian President Bashar Assad has alleged the September 17 attack was a deliberate assault to allow Islamic State militants to take control over the area held by Syrian government troops.
The Defense Department said the airstrike was a mistake and was intended to target Islamic State fighters.
Moscow insisted on an investigation, with Foreign Ministry spokeswoman Maria Zakharova stressing the importance of a probe to determine if the strike was an accident or a deliberate action in support of forces opposing Assad.
The one-hour assault left dozens of Syrian soldiers dead at an airfield near the city of Deir Ezzor, which has been under siege by the Islamic State since July 2014.
