Shipping data revealed a sharp decline in ship traffic through the Strait of Hormuz, following Iran's announcement that the waterway would be closed again due to what it described as "Israeli and American violations" of the ceasefire, according to Iranian and international media.

Kepler data showed only five ships crossed the strait on Sunday, compared with 26 on Saturday, a drop reflecting mounting confusion in one of the world's most important energy arteries.

The data showed that the transiting ships included three giant oil tankers carrying two million barrels of Saudi crude and fuel oil each, one of which was bound for Japan, amid estimates that some ships may have turned off transponders while sailing within the Gulf.

The data indicated that among the ships that exited the strait on Saturday, 3 giant tankers loaded with crude oil from the UAE, Kuwait and Iraq, in addition to 3 tankers carrying various oil products. 13 ships entered the strait on the same day, including two supertankers, while ADNOC and Kuwait Oil issued tenders for the sale of crude with the option of loading from inside or outside the strait, in a move that reflects emergency flexibility in the face of increased risks.

Washington-Tehran talks do not eliminate risks

The maritime turmoil coincided with a drop in oil prices on Monday, after the conclusion of the first round of talks between the United States and Iran in Switzerland, and Tehran's announcement that it would receive waivers for oil and petrochemical exports, easing fears of supply shortages.

Brent crude fell $1.53 to $79.04 a barrel by 06:56 GMT, after touching $82.30 in early trading as tensions escalated and U.S. President Donald Trump's threats to resume war escalated. West Texas Intermediate crude was at $76.53 a barrel, while the most-traded August contract fell to $75.30.

The moves came as U.S. and Iranian officials concluded the first round of talks aimed at extending the ceasefire for another 60 days, as part of a memorandum of understanding reached last week.

Araqchi: Exemptions for Iranian oil and petrochemical exports

Iranian Foreign Minister Abbas Araqchi said that "his country has obtained exemptions for oil and petrochemical exports, in addition to the release of some frozen assets and the launch of a reconstruction and development plan inside Iran."

Tony Sycamore, market analyst at IG, said that "high-level talks between the two sides have led to some progress, which has been an agreement on the formation of a high-level committee," but noted that the effectiveness of these steps will remain dependent on developments on the ground, especially in southern Lebanon.

"A more sustainable agreement will not be easy," ING analysts said, warning of the risk of renewed military action during the 60-day ceasefire.

Oil prices lost more than 8% of their value last week, amid hopes of increasing global supply through the release of pending shipments in the Gulf and the possibility of easing U.S. sanctions on Iranian oil as part of any future deal between Washington and Tehran.