Control of the strait has been the biggest sticking point in efforts to end the conflict. Iran is seeking fees of between 5% and 7% of the price of cargoes from ships using the strait, according to the senior Iranian official. Oman is discussing fees of around 3%, while Washington wants no fees at all. The U.S. Treasury has also prohibited U.S. persons from receiving services from Iran’s government related to a “guarantee of safe passage.” Shipping companies were in a “catch 22” situation, one insurance industry source said, as the LMA wording prohibits insurers from covering shipowners who pay, while Iran aims to charge a toll.