Gasoline prices in the U.S. on Tuesday topped $4 a gallon on average for the first time in more than three years, the latest sign of how the Iran war is driving up fuel costs for U.S. motorists. 

The average price for a gallon of regular gas is now $4.02 a gallon, AAA said, up from $3.99 on Monday and more than $1 from a month ago. The cost of oil, the primary driver of fuel costs, has surged since the U.S. and Israel attacked Iran on February 28. The conflict is disrupting the ship-borne passage of crude through the Strait of Hormuz, the narrow conduit connecting to the Persian Gulf that normally accommodates roughly a fifth of the world’s oil and natural gas.

President Trump has sent mixed messages about his commitment to reopening the strait. On Tuesday, he told CBS News senior White House correspondent Weijia Jiang that he is not ready to abandon efforts to force Iran to reopen the waterway. At the same time, he suggested in a Truth Social post this morning that U.S. allies would need to pursue their own efforts to restore the flow of oil from the region.  

Asked about rising fuel costs, Mr. Trump said U.S. gas prices will drop “when we leave, when it’s over.” 

Separately, White House press secretary Karoline Leavitt also told CBS News in an email on Tuesday that “When Operation Epic Fury is complete, gas prices will plummet back to the multi-year lows American drivers enjoyed before these short-term disruptions.”

Highest gas prices since August 2022

The last time gas was above $4 per gallon was in August 2022. Prices briefly topped $5 per gallon in June of that year after Russia’s invasion of Ukraine sent crude oil prices surging.

“It’s not the shock of $5, but motorists are really going to start to see those digits go up on the dollar price on the pump relatively quickly,” Patrick De Haan, a petroleum expert at GasBuddy, told CBS News.

Since 2009, gasoline has only spent 157 days — all in the year 2022 — above $4 a gallon, according to De Haan.

A CBS News poll released on March 22 found that rising gas prices are heightening concerns about the U.S. economy. In the short term, 90% of respondents expect the Iran war to drive up oil and gas prices, while 58% said fuel costs were likely to increase over the long term. 

Drivers are also noticing the local impact, with 85% reporting higher prices in their area, according to the poll of 3,335 U.S. adults interviewed from March 17-20.

Diesel prices also rose again, reaching $5.454 a gallon Tuesday, compared to Monday’s $5.416. The fuel is commonly used in farming and construction, as well as in trucks, trains and boats that transport American goods. 

As transportation costs increase due to higher energy prices, companies could eventually shift part of the burden onto customers, Diane Swonk, chief economist at KPMG, recently told CBS News.

Research also shows that the additional money Americans spend on gas this year could erase nearly all of the additional money they are slated to collect in tax refunds.

The Trump administration has pulled multiple levers in an effort to tame energy prices, such as releasing oil from its strategic reserve and relaxing government regulations that can push up the cost of petroleum products. 

Analysts, however, told CBS News those measures alone aren’t enough to fill the energy supply gap or ease prices for Americans.