Panetta's comments come as Iran says it can block the waterway.
The strait is a vital sea-lane for a huge amount of the world's oil.
Panetta says, quote, "We made very clear that the United States will not tolerate blocking of the Strait of Hormuz.
That's another red line for us and we will respond to that." Iran has held recent naval maneuvers in the Persian Gulf near the Strait of Hormuz.
The Islamic Republic is under increasing U.S. and international sanctions linked to its nuclear program.
Iran says its atomic ambitions are peaceful.
(Copyright 2012 by VERTEXNews/Newsroom Solutions)