The Pentagon disclosed the location of a U.S. nuclear-armed submarine near the Mediterranean just hours after President Donald Trump rejected Iran's latest counteroffer.

Pentagon Reveals Ohio-Class Nuclear Submarine Deployment

On Monday, the U.S. Sixth Fleet announced that an Ohio-class ballistic missile submarine had arrived in Gibraltar, a rare public acknowledgment involving one of the military's most secretive nuclear assets.

"The port visit demonstrates U.S. capability, flexibility, and continuing commitment to its NATO allies," the Sixth Fleet said in a statement.

It added that Ohio-class submarines are "undetectable launch platforms" that provide the United States with "its most survivable leg of the nuclear triad."

The Pentagon did not identify the submarine by name. Locations of U.S. ballistic missile submarines are typically classified because their stealth is central to nuclear deterrence strategy.

Trump Calls Iran Peace Response 'Unacceptable'

On Sunday, President Trump rejected Iran's response to a U.S.-backed peace proposal, calling it "totally unacceptable" after reviewing it on Truth Social.

He said the message from Iran's representatives did not meet expectations for restarting talks.

A day later, Trump again criticized Tehran's position, saying the ceasefire effort was "on life support" and describing the situation as "the weakest right now." He said Iran's demands were unacceptable.

Iranian officials dismissed the U.S. terms as non-negotiable, calling for an end to military actions, compensation for war damage, restored oil exports, and recognition of Iran's authority over the Strait of Hormuz.

Foreign Ministry spokesperson Esmaeil Baghaei said, "Our demand is legitimate."

Trump Heads To Xi Summit Amid Iran Tensions

Sen. Jack Reed (D-R.I.) said Trump was entering a summit with Chinese President Xi Jinping in a "terribly weakened" position, citing rising tensions with Iran and domestic economic pressure.

Reed referenced a recent Strait of Hormuz clash in which Iranian forces attacked three U.S. Navy destroyers with missiles, drones and small boats.

Trump arrives in Beijing on Wednesday for a meeting with Xi, a trip initially aimed at easing trade tensions but now expected to focus heavily on the war in Iran.