Iran and the Gulf Arab state of Oman have made progress toward a deal to reopen the Strait of Hormuz, a potential breakthrough that could help wind down the war in the Middle East, regional officials said Tuesday, AP reports.

Under the emerging agreement, ships would enter the Persian Gulf through an Iranian-controlled route and exit through a route controlled by Oman, with service fees charged for providing security and preserving the maritime environment, two regional officials told AP.

They said negotiations are still underway and that the final agreement could take a different form, with any deal linked to lifting the US blockade on Iran’s ports.

Any agreement formalizing Iran’s control of the strait would mark a significant strategic victory for Tehran. For that reason, the US could seek to block the deal by refusing to lift the blockade.

A US official familiar with the negotiations said the US remains committed to returning to the status quo in which “no party controls the lanes or the ability to transit through them.”