US President Donald Trump has said he has ordered an investigation into major energy companies, accusing them of "gouging" drivers by not cutting fuel prices after wholesale oil costs fell on global markets.

Speaking to reporters in the White House on Wednesday, Trump said "gasoline prices should be much lower at the pump" as he named Chevron, ExxonMobil, Shell and BP.

His remarks come after wholesale oil prices fell from peaks seen during the US-Israel war with Iran but remain higher than before the conflict started.

The American Petroleum Institute (API), which represents the oil and gas industry in the US, said fuel prices "don't move in lockstep with crude oil".

The BBC has contacted Chevron, ExxonMobil, Shell and BP for comment.

"Oil prices have come down so much and we are not seeing anything at the pump by comparison the way they should be," Trump told reporters in the Oval Office.

"We should be, in my opinion, at $2.25 (£1.71) [a gallon] right now at the pump and we are higher than that."

Earlier, Trump posted on that he believed drivers are being "gouged" by energy firms, adding that he had ordered the Department of Justice (DOJ) to "immediately start looking into this".

"The price of fuel is not only national security issue, it impacts the wallet of every American. We will always commit to ensuring affordability in this nation," a DOJ spokesperson told the BBC without confirming whether an investigation had been launched.

A White House spokesperson 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.

"President Trump has a proven track record of bringing gas prices to historic lows, and the Administration continues to be laser-focused on delivering economic relief for the American people."

In response to Trump's comments, the API's spokesperson Bethany Williams said: "Our industry shares the goal of delivering relief at the pump and restoring stability to global energy markets."

She added that the conflict is "still affecting supply, refining and inventories".