Oil prices gained on Tuesday as the ​resumption of fighting between the U.S. and Iran in the Middle East renewed fears of ‌supply disruptions from the world's key crude-producing region.

Brent crude futures were up 56 cents, or 0.6%, to $91.05 a barrel at 0044 GMT, while U.S. West Texas Intermediate crude was up 83 cents, or 1%, to $86.59.

In the previous session, Brent closed up 2.7%, at ​one point reaching its highest since August 25, and WTI settled up 2.8%, touching its highest ​since August 21.

On Monday, U.S. President Donald Trump threatened further strikes against Iran following the first ⁠exchange of direct attacks between the countries in a month on Sunday, raising tensions in a conflict ​that had recently shifted into an economic standoff.

"These bring the potential for Iranian retaliation back into the equation. That ​, in turn, raises the prospect of damage to energy infrastructure around the Gulf and adds fresh uncertainty for shipping through the Strait of Hormuz.

Both of those risks are being reflected in the firmer tone in crude prices," said Tim Waterer, chief market ​analyst at KCM.

Over the weekend, the number of visible commodity vessels transiting the Strait of Hormuz dropped to five per day, according to shipping data from Kpler.

Efforts by mediators including Qatar and Oman to broker a deal to reopen the ‌Strait of ⁠Hormuz, which carried about a fifth of global oil supplies before the war erupted in late February, have so far failed to gain traction.

Iran shut the waterway after the U.S. and Israel attacked the country on February 28.

Highlighting the risks that remain to shipping and oil supply, the United Kingdom Maritime Trade Operations agency (UKMTO) said on Tuesday ​that a tanker reported being struck by three projectiles while sailing out of the Strait of Hormuz. No casualties or environmental impact were reported.

On Friday, Trump announced a deal with Venezuela to control the country's oil reserves, which he later said would help replenish the U.S. Strategic Petroleum Reserve, which is near a 44-year low.

U.S. companies ⁠Chevron and GE Vernova, India's ONGC, Italy's Eni and Colombia's GeoPark are on track to sign final agreements in Venezuela after months of negotiations to firm up energy projects in the OPEC country, five sources close to the preparations ⁠said on ​Monday.

Crude oil inventories in the U.S. Strategic Petroleum Reserve declined by about ​3.1 million barrels last week, leaving stockpiles at 286.6 million barrels.

Analysts polled by Reuters in August expect oil prices to remain above $80 a ​barrel in 2026 as shipping disruptions continue.