Shipping companies said on Monday that President Trump’s offer to provide them safe passage through the Strait of Hormuz fell short of the sort of arrangements that would persuade them to make the trip.
Mr. Trump said on Sunday that the United States would “guide” commercial vessels through the strait, which Iran has effectively closed since the war in the Persian Gulf started two months ago. But the president provided few details on how the program, Project Freedom, would work.
On Monday, the United Arab Emirates accused Iran of launching a drone attack on an oil tanker owned by ADNOC, its state oil company, according to the Emirati state news agency.
Ali Abdollahi, a top Iranian military commander, warned “all commercial ships and oil tankers to refrain from any attempt to transit without coordination with the armed forces,” Iranian state media reported on Monday.
Fearing attacks by Iran on their vessels, shipping companies have been reluctant to send vessels through the strait. They say Iran needs to be part of any plan to move large numbers of vessels through the waterway.
Without an agreement from Iran, “there is a risk of hostilities breaking out again,” said Jakob P. Larsen, the chief safety and security officer of the Baltic and International Maritime Council, which represents companies in the maritime sector.
“It is unclear whether Project Freedom is sustainable in the longer run or whether it will be a limited operation to get some of the trapped ships out,” Mr. Larsen added.
Tom Bartosak-Harlow, a spokesman for the International Chamber of Shipping, a maritime trade group, said Mr. Trump’s plan lacked detail.
“There is much uncertainty around what Project Freedom means in practice, but any plans put in place must be done in a coordinated and transparent manner,” he said in a statement. Mr. Bartosak-Harlow said the chamber was calling on all countries, Iran included, “to work together to seek a swift and transparent resolution to restore freedom of navigation.”
Iran’s stranglehold on the strait has cut off a significant proportion of the world’s supply of oil and natural gas.
Oil prices initially fell on the news of Mr. Trump’s operation, but then jumped on Monday in volatile trading. Tensions between the United States and Iran have underscored the risks surrounding maritime traffic through the strait, a critical energy choke point.
Despite assurances from Mr. Trump that any interference in the program would be dealt with “forcefully,” ships trying to transit the Strait of Hormuz have been reluctant to take the chance after reports of attacks on Sunday.
“The number of vessels passing the strait remain minimal, averaging five a day, but with only three in the last 48 hours,” Bob Savage, the head of markets strategy at BNY, wrote in a research note on Monday. Most of the ships that have gone through the waterway since the war began have taken a route that runs close to Iran’s coastline, indicating that the ship operators got Iran’s permission to make the passage.
Insurance costs are a main reason cargo ships are not traveling through the strait, Ana Subasic, a trade risk analyst at Kpler, said in an email. “Even if a captain is willing to sail, owners, lenders, charterers and cargo interests may refuse to,” she added.
“Project Freedom has a moderate chance of extracting some vessels, especially U.S.-flagged or highly coordinated low-risk vessels, but a low chance of fully reopening Hormuz quickly unless it becomes legally clear, less expensive and diplomatically coordinated,” Ms. Subasic said.
The United States has set up a military blockade southeast of the Strait of Hormuz in the Gulf of Oman to prevent Iranian ships transporting the country’s oil to world markets.
If Mr. Trump were to use military force to get ships through the strait, it would raise questions about whether the United States was providing some form of escort to commercial vessels. Early in the war, Mr. Trump suggested that the United States might deploy naval vessels as escorts, but later he called on other countries to do so.
Before Mr. Trump’s announcement, a vessel near the strait had been hit by projectiles and a second had been attacked by multiple small craft, the United Kingdom Maritime Trade Operations, a security center that is administered by Britain’s Royal Navy, reported on Sunday.
“Lives of sailors are in utmost danger — they have such scarcity of drinking water,” said P.A. Khan, who oversees the branch of the Maritime Union of India in Chennai, India. “What Trump is saying makes things more difficult and not easier.”
The International Maritime Organization, which monitors developments, said about 20,000 mariners on around 1,600 vessels were trapped in the Persian Gulf. “My call is to release the seafarers because they are not at fault,” Arsenio Dominguez, the group’s secretary-general, said in a statement last week. “The situation is not improving.”
Nearly 30 ships have been attacked since the war began, according to the organization.
Suhasini Raj contributed reporting from New Delhi, and Vivian Nereim from Riyadh.
