The Turkish National Defense Ministry said the probe began early Wednesday in coordination with Georgian authorities.
“At 06:30 a.m. (0230GMT), in coordination with Georgian authorities, the search and rescue and accident investigation team began its investigation of the wreckage of our military cargo plane that crashed on the Azerbaijan-Georgia border,” the ministry said.
A Turkish C-130 cargo aircraft carrying 20 military personnel went down Tuesday after departing from Azerbaijan en route to Turkey.
Turkish President Recep Tayyip Erdogan spoke separately with Azerbaijani President Ilham Aliyev and Georgian Prime Minister Irakli Kobakhidze to discuss the ongoing rescue operations.
Speaking at an event in Ankara, Erdogan offered condolences for those killed.
The number of casualties and the cause of the crash remain unclear.
Leaders and governments worldwide expressed solidarity with Turkey following the accident.