Iran is taking steps to cement its control over the Strait of Hormuz and to generate revenue from the waterway through new entities and procedures, experts say. The moves come even as negotiations with the United States and Iran’s neighbors over managing the vital waterway are taking place.

The head of Iran’s primary insurance regulator, Mousa Rezaei, said on Sunday that a new insurance company had been established that was dedicated solely to the Strait of Hormuz, Iranian state media reported. And late last week, the Persian Gulf Strait Authority, which was created by Iran in May, demanded that vessels register and sign up for a new mandatory Iranian insurance policy — free of charge for now.

Shipping experts see these steps as an attempt to assert Iranian control over the whole waterway, which it shares with Oman. They appear to be a prelude to Iran’s demanding payments from vessels that once transited without fees or need of its assent, the experts say.

The Iranian requirements could set a dangerous precedent for global shipping, experts say, and they are already making a confusing situation in the strait much more so.

“We are in uncharted territory,” said Richard Meade, editor in chief of Lloyd’s List, a shipping news service, in an interview on Monday.

The Persian Gulf Strait Authority did not respond to a request for comment.

The insurance demands emerged after the United States and Iran signed a memorandum of understanding to end the war and to reopen the Strait of Hormuz last week. That agreement left discussion of difficult issues — including management of the strait — to further talks. And Oman, Iran and other Gulf nations “will figure out a proper security framework for the straits in the future,” Vice President JD Vance said last week.

But the Iranian demands try to legitimize the authority of the new entity as those broader negotiations are underway, said Salvatore Mercogliano, a maritime historian and former merchant marine who hosts the YouTube show “What’s Going On With Shipping?”

The free insurance period passes after 60 days, which is the length of the initial cease-fire agreement between Tehran and Washington and the period that the initial deal guarantees free passage. After that Iran could then demand vessels pay for insurance through its new dedicated strait insurance company, Mr. Mercogliano said, collecting payment for risks that did not exist until Iran began attacking ships.

The new insurance that Iran is offering protects against things like risk of attack and the detention of mariners, issues that experts say Iran created after the United States and Israel attacked the country in February and it retaliated by striking commercial vessels.

Iran weaponized the waterway by making it too dangerous for businesses, experts say.

Mr. Mercogliano said in an interview that the new administrative procedures took this Iranian weaponization a step further. He compared the insurance requirement to the mafia’s demanding protection money or someone trying to sell flood insurance “while they control the gates above the dam.”

The new Iranian insurance also raises legal questions. Under international law, a toll for mere passage through the strait would be illegal, though charging fees for services — tugging or waste disposal, for example — could be legal.

Since March, Iran has floated the notion that it will charge ships in the strait, characterizing the payments as services without specifying what it would offer and raising international alarm. Last month, it was in talks with Oman about the proposition.

But simply calling something a “service” is not enough to transform an illegal toll into a legitimate request for payment for services, maritime lawyers say.

The Persian Gulf Strait Authority’s insurance demand “effectively sidesteps” the agreement between the United States and Iran and paves the way for Iran to demand fees in the future, Mr. Meade, of Lloyd’s List, said.

“This is effectively a toll by another name,” he said.

A spokeswoman for the International Maritime Organization told The New York Times that the insurance requirement published by the authority “has not been officially submitted to I.M.O. and is not part of any official process or record.”

She said that the right of ships to transit passage through the passage “cannot be suspended or hampered by coastal states” and that there was “no established basis in international law” that allowed mandatory tolls or fees. She did not, however, rule out “cooperation mechanisms to assist in managing a strait” between states.

The new insurance requirement also raises practical questions for shippers and vessels. By having to pay to mitigate risks from Iran, businesses could find themselves in trouble with the United States.

The Treasury Department imposed sanctions on the Persian Gulf Strait Authority in late May. The United States called the entity a new attempt by Iran “to monetize its campaign of state-sponsored terror by extorting vessels,” and Treasury warned against paying the authority, saying that those who did do so could be subject to sanctions.

Iran is also under a number of different sanctions from the United States, Britain, the European Union and the United Nations. While lifting the sanctions has been discussed as part of a broader deal related to Iran’s fulfilling commitments to end its nuclear program, at this stage, registering for Iranian war-risk insurance is itself a potential risk.

In light of the confusion about navigating the strait, shippers are in “purgatory,” stuck between a past that cannot be revived and a future that remains unclear, Mr. Meade said.