The Defense Department is conducting an initial review of the mission in Niger and the ambush by 50 ISIS-affiliated fighters that left four US soldiers dead and two wounded.

Multiple US officials have described to CNN a scene of confusion on the ground during the unexpected firefight. The investigation will be an effort "to get all the facts correct," an administration official familiar with the review told CNN.

The review will aim to determine precisely what happened -- something that is still not clear nearly two weeks after the incident occurred, according to the official.