Iran’s Persian Gulf Strait Authority has issued a document requiring all vessels to hold insurance approved by the authority in order to pass through the Strait of Hormuz.

According to Odaily, the document says the insurance is free during the period specified in a memorandum of understanding between the United States and Iran, but it may be charged later.

The Financial Times reported that the document has been circulated among shipping industry management. The document states that “all vessels must hold a valid insurance policy approved by the Persian Gulf Strait Authority.” It adds that the insurance currently carries “no charge,” while the authority “reserves the right to charge premiums in the future.”