By Irina Slav for OilPrice.com

President Donald Trump has listed Exxon, Chevron, Shell, and BP as being among companies responsible for excessively high fuel prices, following the announcement of a federal government probe into price-gouging earlier in the week.

“Oil prices have come down so much and we are not seeing anything at the pump by comparison the way they should be,” the U.S. president told media, as quoted by the BBC. “We should be, in my opinion, at $2.25 [a gallon] right now at the pump and we are higher than that.”

The U.S. national average for a gallon of regular gasoline was $3.928 as of Wednesday, down from $4.0250 a week ago, but up from $3.2240 a year ago, according to AAA data. GasBuddy reported a national average of $3.85 per gallon as of Monday. Still, fuel prices have been on a decline for six weeks in a row, with diesel also dipping below $5 per gallon for the first time in weeks, bringing relief to industrial fuel consumers.

“The big Oil Companies are not dropping their price at the pump commensurate with the sharply lower prices they are paying for Oil. Those prices are dropping like a rock! In other words, customers are being "gouged",” Trump wrote on TruthSocial late on Tuesday. “I have instructed the DOJ to immediately start looking into this. Gasoline prices better start going down a lot faster than what I’m seeing!” the U.S. president also wrote.

In response, the American Petroleum Institute said that retail fuel prices “don't move in lockstep with crude oil”. “Our industry shares the goal of delivering relief at the pump and restoring stability to global energy markets,” API spokeswoman Bethany Williams also said.

“President Trump was clear all along that there would be short-term, temporary disruptions to energy markets, and that oil and gas prices will quickly fall as soon as the Iran situation is resolved,” a White House spokesperson told media, as quoted by the BBC.