Australian diesel prices could rise above $3 per litre if former U.S. President Donald Trump restricts U.S. diesel exports, a move being considered as part of his efforts to lower fuel prices domestically ahead of the November U.S. midterm elections. Diesel prices have already climbed to levels not seen since early April, increasing inflationary pressures and making another interest rate hike more likely. In Canberra, the capital, diesel costs reached 298.7 cents per litre, while unleaded fuel was priced at 250 cents per litre on Thursday, with other major cities showing only minor differences. Over the past month, prices have risen nearly 40 cents per litre, adding about $22 to the cost of filling a typical 55-litre car tank. The rise in fuel prices is largely due to increased costs passed on by international refineries, which are struggling to secure affordable oil. Ongoing conflicts in the Middle East have disrupted oil supplies, preventing them from reaching global markets. The price of Brent crude oil, a key benchmark, has stayed above $100 per barrel for most of the past two weeks, hitting its highest point since May. Gulf countries are now exporting only a quarter of their pre-war diesel levels, with ongoing conflict limiting the movement of fuel tankers through the Strait of Hormuz and the Bab al-Mandab Strait. Meanwhile, Ukrainian attacks have also disrupted Russian oil supply, further tightening global fuel markets. If Trump's administration imposes a ban on U.S. diesel exports, it could exacerbate the shortage, given that the U.S. has significantly increased its global diesel supply since the war began, exporting over 1.5 million barrels per day. Australia, which relies heavily on imported diesel, has imported over 18.4 billion litres from January to July 2026, with only about 510 million litres coming from the U.S. Analyst Saul Kavonic from MST Financial warned that a U.S. export ban could lead to diesel rationing in Australia and prices potentially exceeding $4 per litre within weeks. However, Dr. Lurion De Mello from Macquarie University said Australia's supply remains stable, with diesel stockpiles at 31 days' worth, the same as in March. He noted that prices could rise above $3.10 per litre but would likely stay below $3.50 as long as Asian refiners continue to access oil. The Australian government temporarily reduced the fuel excise tax in March when diesel prices surpassed $3.10 per litre, but no further reductions have been announced. High fuel costs could impact industries reliant on imported diesel, such as farming and mining, and lead to higher prices across food, manufacturing, and transport sectors. The Reserve Bank is expected to raise interest rates to 4.6%, a 14-year high, partly due to the upward pressure on fuel prices.