The Iranian revolutionary guard threatened ships seeking to transit through the Strait of Hormuz without coordination with its officials.
CNBC noted that officials described such scenarios as "unacceptable and dangerous," adding that vessels ignoring its instructions could face retaliation.
The guard's navy said only shipping routes approved by the country are allowed, and coordination with officials is mandatory.
The outlet detailed that the threat comes after a key naval information group proposed alternative routes on Saturday.
Transit is recovering despite the threats. Data provider Marine Traffic noted that 93 vessels made it through the strait last weekend, three times as much as the previous one, but still below historical averages.
U.S. Energy Secretary Chris Wright appeared to challenge the Iranian guard, saying the country's military escorts to ships mean Iran no longer has the ability to close the Strait of Hormuz.
Speaking at a conference in New York City, Chris Wright said such actions from Tehran are "their key leverage and we're taking that leverage away from them."
He went on to claim that 17 million barrels of oil went through the key waterway even though Iran said during the weekend it was closed. And added that 72 ships carrying 19 million additional barrels went through the strait in the past 24 hours.
Elsewhere, Wright said that the Trump administration could reimpose its blockade of Iranian ports if negotiations between Washington and Tehran are unfruitful.
"If we can get no deal with Iran, we will assure that the flow of energy is there, the world is well supplied and the Iranian administration will be in a world of hurt," he said.
Oil prices have plunged since the countries reached an agreement to end the war and reopen the key waterway.
The United Nations' maritime agency has also begun implementing a large-scale operation to evacuate more than 11,000 seafarers stranded aboard hundreds of vessels in and around the Strait of Hormuz.
According to the International Maritime Organization (IMO), the evacuation effort will involve close cooperation among Iran, Oman, other Gulf coastal states, the United States, and the global shipping industry. "We will begin the implementation of the evacuation plan for over 11,000 seafarers still stranded in the region," IMO Secretary-General Arsenio Dominguez said in a statement announcing the operation.
The agency said it had secured the necessary safety guarantees and verified conditions for safe navigation before proceeding.
