WASHINGTON (AP) " Dramatic new drone video of the Niger ambush that killed four American soldiers shows U.S. forces desperately trying to escape, and fighting for their lives after friendly Nigerien forces mistook them for the enemy.

It shows how the fleeing troops set up a quick defensive location on the edge of a swamp and " thinking they were soon to die " wrote messages home to their loved ones.

The nearly 23-minute video was released by the Pentagon with explanatory narration. It includes material that wasn't made public last week when the Pentagon released a final report on the attack.

U.S. and Nigerien forces were ambushed after an October mission to track down a high-level militant in the west African nation. Four Nigeriens also were gunned down.