Trump urges Zelenskyy to halt strikes on Russian oil refineries as U.S. diesel prices hit record high

U.S. President Donald Trump has urged Ukrainian President Volodymyr Zelenskyy to stop targeting Russian oil refineries, saying the attacks are "hurting the world" as fuel supply disruptions from the Ukraine and Iran wars propel U.S. diesel prices to a record high.

Ukraine has stepped up its attacks on Russian oil facilities and logistics infrastructure in recent months, seeking to raise the cost of the war for Moscow after more than four-and-a-half years of conflict.

The attacks have significantly hampered Russia's refining capacity and prompted widespread fuel shortages, with Moscow recently extending a ban on diesel exports through the end of September as part of a push to stabilize domestic supplies.

"Mr. Zelenskyy has to do one thing. He has to stop knocking out diesel fuel in Russia," Trump said during an official visit to Ireland on Sunday.

"Let him go after targets but not diesel fuel because he's causing a shortage of diesel. This isn't done by the Middle East; this is done by what's happening with Russia and Ukraine."

A spokesperson for Ukraine's Foreign Ministry was not immediately available to comment when contacted by CNBC on Monday morning.

Ukraine, which fears an extremely difficult winter period amid expectations of another Russian assault on its energy infrastructure, has previously characterized Russian oil refineries as legitimate military targets.

Trump's warning comes shortly after the price of diesel, a critically important fuel for everything from heavy-duty transportation and commercial shipping to industries like mining and agriculture, topped $6 per gallon for the first time ever on Friday.

The average price nationwide stood at $6.06 per gallon, according to data from AAA, with truckers and farmers now paying about 63% more to fill up their semis and tractors than they did this time last year.

The sharp rise in diesel prices coincides with a jump in crude oil prices as fighting continues between the U.S. and Iran in the Middle East.

International benchmark Brent crude futures with November expiry rose 2.1% to $106.69 per barrel on Monday morning, extending gains after jumping more than 20% over the past month.

U.S. West Texas Intermediate futures with October expiry, meanwhile, traded 2.1% higher at $102.15. The contract, which is up nearly 25% over the past month, surpassed $100 for the first time since May last week.