Iran is seeking to charge fees for ships passing through the Strait of Hormuz, a crucial energy waterway, as part of its proposals to end the war with Israel and the United States.
The fee would vary depending on the type of ship, its cargo, and other conditions, according to a senior Iranian official.
Oman has held talks with Iran on options to ensure smooth transit, but no agreements have been reached.
Shipping industry officials say no country has ever made a unilateral move to demand fees to traverse a strait.
The United States and Gulf states are concerned that Iran's proposal could restrict free navigation through the Strait.
International law says states bordering straits cannot demand payment simply for permission to pass through, but they can impose limited fees for specific services.
Canals, such as the Suez and Panama Canals, charge fees to pass through, but straits are treated differently.
