The U.S. military will not allow Iran to shut down the Strait of Hormuz, Secretary of Defense Leon Panetta said Wednesday, adding that if Iran tries to disrupt the vital waterway, they will be defeated.

Iran’s leaders have threatened to close down the Strait unless sanctions against their critical oil shipments are lifted. The Pentagon chief said the U.S. will not allow either Iran or any of its allies to stop shipping through the Strait.

“Iranians need to understand that the United States and the international community are going to hold them directly responsible for any disruption of shipping in that region by Iran or, for that matter, by its surrogates,” Panetta said, adding, “and the United States is fully prepared for all contingencies.”

Panetta’s comments came on the heels of the Pentagon’s announcement that the U.S. Navy would accelerate the deployment of the USS John Stennis carrier group to the Gulf region. The more than 5,000 sailors will deploy about four months earlier than originally scheduled so the U.S. can maintain a two-carrier presence in the area through the end of the year.

Related: USS Stennis going to Persian Gulf early, staying longer

Speaking with his British counterpart after their early-morning meeting, Panetta said that the U.S. has invested in capabilities in the region to “ensure that the Iranian attempt to close down shipping in the Gulf is something that we are going to be able to defeat if they make that decision to do that.”

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Secretary Phillip Hammond echoed Panetta's sentiments, saying that the deployment of the USS John Stennis carrier group to the Gulf sends a “powerful signal” to Iran.

Hammond’s comments came just days after Pentagon Press Secretary George Little denied that the accelerated deployment of the Stennis was a direct response to tensions with Iran.

“This is not a decision based solely on the challenges posed by Iran,” Little said on Monday, adding that the deployment of the Stennis is not intended to send a signal to Iran.

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