Fuel costs have risen to levels not seen since early April, adding to inflation risks and making another interest rate hike all but certain, the Guardian reported. Australian diesel prices could surge beyond $3 a litre if Trump follows through on cutting exports, exacerbating pressure on farmers and trucking companies already struggling with high costs.

In the United States, the average price for a gallon of diesel hit $5.85 on September 4, according to the American Automobile Association (AAA)—up from $3.71 a year ago and surpassing the previous high after Russia's invasion of Ukraine. Diesel in the US is primarily used by commercial vehicles such as trucks, trains, boats, buses, and farming and construction equipment.

Fuel prices have soared since the Iran conflict began at the end of February, reflecting the surge in wholesale oil prices after Iran effectively closed the Strait of Hormuz in response to the war.

In response to rising fuel costs, Trump recently pledged to "substantially lower Gas Prices for all Americans" through an oil deal with Venezuela. The agreement, announced in early September, calls for the development of 17 strategic oil fields with a proven potential of 65 billion barrels, as well as investment of more than $100 billion and more than $209 billion in taxes for Venezuela, according to Interim Venezuela President Delcy Rodriguez. The US government will retain 55% control of a joint venture with an "experienced private operator in Venezuela," a US official told CBS News. However, some analysts have reacted with skepticism, questioning whether the deal would address long-running obstacles that have deterred investment in Venezuela's oil industry.

Meanwhile, the global diesel crunch is hitting agriculture hard. In Australia, grain farmers are facing an expensive harvest after already paying more for fuel and fertiliser during sowing earlier this year. Victorian Farmers Federation President Ryan Milgate said high diesel prices would "really, really bite on the bottom line," adding, "We're getting a bit of deja vu where the price seems to be heading north again." Trucking business owner Dan Russo, who runs a fleet of 13 semi-trailers from Melbourne, said the return of high diesel prices is "crippling the trucking industry" and warned that extra costs will eventually flow on to consumers. "No-one wants to see $10 bottles of milk at the supermarket," he said.

The record diesel prices could feed through to consumer price inflation, confirming expectations of more Federal Reserve rate hikes. The central bank appears determined to raise rates into an oil supply shock, CoinDesk reported.