Crude oil prices extended their earlier gains after President Trump issued a fresh threat against Iran following the first exchange of fire in weeks.

At the time of writing, Brent crude was trading at $91.48 per barrel, while West Texas Intermediate was at $86.97 per barrel. Both benchmarks were up by more than $1 per barrel from Monday.

Speaking at the Oval Office on Monday evening, Trump said the United States was ready to "smack" Iran if necessary.

Shipping data show that tanker traffic in the Strait of Hormuz remains at a fraction of pre-war levels. Reuters cited figures suggesting that daily oil flows out of the Persian Gulf averaged 6 million barrels, while Kpler data showed just five commodity vessels passing through the waterway on Monday. Reuters noted that this was below the 10-day average of 14 vessels.

The strait is one of the world’s most important oil transit routes, so even reduced traffic there can quickly draw attention from refiners, shippers, and traders watching for any disruption to crude and product supplies. That is especially relevant as the market heads into a period when seasonal demand often strengthens and spare buffers are already being tested.

“Oil producers in the region have grown more comfortable shuttling crude through the key chokepoint in recent weeks,” ING commodity analysts wrote in a note on Monday. “Reports have 6-8m b/d transiting the strait, although we assume an average of 5m b/d. Further escalation could put these flows under renewed pressure.”

“Despite satellite tracking firms suggesting oil flowing through Hormuz is around 6 million barrels per day, that is well below pre-conflict levels," ANZ analysts said in a note cited by Reuters.

“In the meantime, the buffers the global oil market has been relying on are becoming exhausted. U.S. inventories are nearing minimum levels, while China's ability to keep imports low will be tested as seasonal demand picks up.”

The analysts’ comments reflect growing unease in oil markets over supply security as demand begins to rise on seasonal factors. The supply situation is more acute in diesel, where tighter availability can matter for transport, agriculture, and industrial activity.

Diesel, often described as the workhorse of the economy, is already in tight supply, and that squeeze is deepening. Russia has extended its diesel export ban until the end of this month amid continued Ukrainian strikes on its refineries. Diesel exports from the Middle East are also being constrained by the Hormuz blockade and refinery damage across the region.

By Irina Slav for Oilprice.com