Pentagon spokesman John Kirby told NBC News there was "no reason to doubt the authenticity" of the clip purporting to show US soldier Sergeant Bowe Bergdahl, who has spent five years in Taliban captivity, being handed back into US custody.
He said: "US officials are currently reviewing the video, but our focus right now is in getting Bergdahl the care he needs."
More top news
The Duke and Duchess of Cambridge went salmon fishing in Canadian waters on the latest leg of their royal visit to the country.
What happens when a former president holds up a current president hoping to fly home for dinner with his family?
Following a bruising televised debate with Hillary Clinton, Donald Trump's week seems to have only got worse.