Iran and the U.S. have received a proposal to end hostilities that could take effect Monday and reopen the Strait of Hormuz, a source familiar with the plan said.
The framework has been put together by Pakistan and exchanged with Iran and the U.S. overnight, the source said, outlining a two-tier approach with an immediate cease-fire followed by a comprehensive agreement.
"All elements need to be agreed today," the source said, adding the initial understanding would be structured as a memorandum of understanding finalized electronically through Pakistan, the sole communication channel in the talks.
Axios first reported Sunday that the United States, Iran and regional mediators were discussing a potential 45-day cease-fire as part of a two-phase deal that could lead to a permanent end to the war, citing U.S., Israeli and regional sources.
The source told Reuters Pakistan's army chief, Field Marshal Asim Munir, has been in contact "all night long" with U.S. Vice President JD Vance, special envoy Steve Witkoff and Iranian Foreign Minister Abbas Araghchi.
Under the proposal, a cease-fire would take effect immediately, reopening the Strait of Hormuz, with 15-20 days to finalise a broader settlement.
The deal, tentatively dubbed the "Islamabad Accord," would include a regional framework for the strait, with final in-person talks in Islamabad.
There was no immediate response from U.S. and Iranian officials. Pakistan's foreign office spokesperson Tahir Andrabi declined to comment.
Iranian officials have previously told Reuters that Tehran was seeking a permanent cease-fire with guarantees they will not be attacked again by the U.S. and Israel. They have said Iran has received messages from mediators, including Pakistan, Türkiye and Egypt.
The final agreement is expected to include Iranian commitments not to pursue nuclear weapons in exchange for sanctions relief and the release of frozen assets, the source said.
Two Pakistani sources said Iran has yet to commit despite intensified civilian and military outreach.
"Iran has not responded yet," one source said, adding proposals backed by Pakistan, China and the United States for a temporary cease-fire have drawn no commitment so far.
There was no immediate response from Chinese officials to requests for comment.
The latest diplomatic push comes amid escalating hostilities that have raised concerns over disruption to shipping through the Strait of Hormuz, a critical artery for global oil supplies.
U.S. President Donald Trump has in recent days publicly pressed for a rapid end to the conflict, warning of consequences if a cease-fire is not reached within a short timeframe.
The conflict has heightened volatility in energy markets, with traders closely watching any developments that could affect flows through the strait.