Oil touches $97 per barrel as diesel prices surge to highest level this year

A monthlong run of rising crude oil prices and refineries' nearing capacity has pushed the average cost of diesel fuel to its highest since 2022.

At $5.78 per gallon Thursday, the cost of diesel is up more than 53% since the war with Iran started in late February. At the time, it was $3.76 nationwide.

The price of unleaded gasoline, which most personal vehicles run on, rose alongside diesel Thursday. According to AAA data tracked by NBC News , the national average was $4.14 per gallon, up 2 cents from Wednesday.

Around the world, crude oil prices also keep climbing. The international oil benchmark Brent surpassed $97 per barrel Thursday morning but ended the day nearly unchanged at $95.52. The price of Brent is up 20% since Aug. 4.

But experts are focused this week on diesel, the fuel that powers everything from boats and trains to farm equipment and 18-wheelers. Around the world, planting and harvesting depend on diesel-powered machines. As a result, higher diesel prices now could mean higher grocery prices in the fall.

Several factors are fueling the global rise in energy prices. Chief among them is the war in Iran, which analysts view as a stalemate that has choked major maritime arteries for oil and gas.

Recent attacks on ships in the critical Strait of Hormuz, coupled with retaliatory U.S. strikes on Iranian targets, mean daily vessel traffic in the waterway remains minimal. Before the war, the strait was a key passageway through which about 20% of the world's oil supply passed every day.

Also putting pressure on gas prices this week is the recent escalation of the Ukraine war.

"Following Ukrainian drone attacks on refineries, Russia has banned diesel exports until the end of September amid domestic supply concerns," ING commodities analysts wrote. "This matters because Russia is the world's second-largest diesel exporter. Combined disruptions are equivalent to around 20% of global seaborne diesel trade."

Only two developments can realistically be expected to bring meaningful relief to oil and gas prices, they wrote. One is a higher flow of oil and gas through the Persian Gulf, and the other is a resumption of Russian diesel exports.

On Wednesday, President Donald Trump said the latest round of U.S. strikes on Iran would not last "too long," but he added, "We're prepared to do another one any time we want."

He also said U.S. forces were "bringing lots of boats out" of the Strait of Hormuz every day.

Trump's upbeat comments did little to ease oil price pressures, however.