President Donald Trump criticized “big oil companies” for not lowering prices for consumers, even though oil purchase costs have dropped. He accused oil companies of price gouging consumers, ordered the Department of Justice to investigate current practices, and demanded that the country’s gas prices drop quickly. Trump issued the rebuke to oil companies in a Truth Social post shortly after midnight on Wednesday.

“The big Oil Companies are not dropping their price at the pump commensurate with the sharply lower prices they are paying for Oil,” said Trump in his post. “Those prices are dropping like a rock! In other words, customers are being ‘gouged.’ 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!”

Worldwide oil prices soared after the United States initiated Operation Epic Fury against Iran on Feb. 28. During the conflict, Iran closed the Strait of Hormuz, arguably the world’s most essential energy chokepoint, with approximately 25% of global seaborne oil trade passing through it, causing economic shockwaves in the oil industry. U.S. West Texas Intermediate crude oil hit a high price of $119.47 per barrel on March 9, while Brent Crude oil reached a high of $126.41 on April 30, the highest price in over four years.

Recently, oil prices have dropped amid rumors of a peace deal being negotiated between the countries. Oil costs hit a three-month low earlier in June after Trump announced an agreement had been reached. As of early Wednesday morning, Brent Crude oil was priced at $76.22 per barrel while WTI oil was at $72.28 per barrel.

Gas prices in the U.S. have also steadily declined over the last month as a result, corresponding with falling oil prices and rumors of peace between Iran and the U.S. As of June 23, the national average price for a gallon of regular gas was $3.926, down from $4.529 a month ago.