Mexico's navy says it is still searching for a lone survivor approximately 400 miles (643km) from the Pacific coastal city of Acapulco.
It is the latest in a series of attacks on boats the US says have been carrying drugs in both the Pacific and Caribbean.
The latest strikes in the eastern Pacific, which Hegseth said happened on Monday at the direction of President Donald Trump, mark an escalation in what it has cast as a campaign to stop narcotics from entering the US
