The United States has quietly delivered a sweeping 15-point ceasefire proposal to Iran through Pakistani intermediaries, even as tensions continue to escalate and both sides show little willingness to back down.

The plan, described by officials in Islamabad and individuals briefed on its contours, outlines a broad framework aimed at ending the conflict, even as Washington simultaneously reinforces its military presence in the Middle East with additional troops and Marine units heading to the region.

According to those familiar with the proposal, the 15-point plan addresses the core disputes between Washington and Tehran, including sanctions relief, civilian nuclear cooperation, and a rollback of Iran's nuclear program.

It also calls for enhanced monitoring by the International Atomic Energy Agency, limits on Iran's ballistic missile capabilities, and guarantees for shipping access through the Strait of Hormuz.

The strategic waterway, through which roughly a fifth of the world's oil supply passes, has become a central flashpoint, with Iran's actions targeting regional energy infrastructure and exerting pressure on the Strait sending oil prices sharply higher and rattling global markets amid fears of a broader energy crisis.

Pakistan has offered to host renewed negotiations between the two sides, positioning itself as a key intermediary in any potential talks.

However, the diplomatic outreach comes at the same time as a significant U.S. military buildup.

The Pentagon is preparing to deploy at least 1,000 troops from the 82nd Airborne Division, adding to an estimated 50,000 American personnel already in the region.

Two Marine Expeditionary Units are also being sent, contributing roughly 5,000 Marines and thousands of sailors.

Officials have framed the parallel tracks of diplomacy and military reinforcement as an effort to give President Donald Trump "maximum flexibility" in deciding whether to escalate or pursue a negotiated settlement.

Despite the proposal, Iran has so far dismissed the ceasefire effort outright. An Iranian military spokesperson, Lt. Col. Ebrahim Zolfaghari, mocked the initiative, suggesting that the United States was "negotiating with itself" and portraying the outreach as a sign of weakness.

He reiterated that Iran would not come to terms with Washington under current conditions, declaring that stability in the region would be secured through the strength of Iran's armed forces.

His comments came as Iran launched a new wave of attacks across Israel and the Persian Gulf region, including a strike that triggered a major fire at Kuwait International Airport, sending thick black smoke into the sky and intensifying concerns about further escalation.

Iranian officials have also pushed back against claims of direct negotiations. While Iranian Foreign Minister Abbas Araghchi has been in contact with counterparts to discuss the war, parliamentary speaker Mohammad Bagher Ghalibaf denied assertions by Trump that talks were underway.

At the same time, Trump has suggested that Iran may be open to a deal, even claiming the country had offered an oil- and gas-related "present," a statement that has not been substantiated by Iranian authorities.

The ceasefire proposal has also created unease among U.S. allies. Israeli officials, who have been advocating for continued military pressure on Iran, were reportedly taken by surprise by Washington's decision to pursue a diplomatic track.

The Associated Press contributed to this report.