With diesel prices hitting a record $6.27 a gallon, Washington is talking about a maneuver that could ultimately make matters worse

The U.S. is the world's largest exporter of diesel.

The Senate's top Republican said he's open to discussing an export ban on diesel as the price of the fuel reached new heights on Tuesday.

The average price of diesel in the U.S. hit an all-time high of $6.27 per gallon on Tuesday, according to AAA, up about 80 cents from a month ago. A year ago, the price was $3.69 a gallon.

Senate Majority Leader John Thune told reporters at the U.S. Capitol on Tuesday that he's "open to considering" a diesel export ban as one way to take pressure off diesel prices.

With the midterm elections about seven weeks away and the war with Iran at an impasse, that could be a Band-Aid solution to curb prices in the near term. Market participants are quick to point out, however, that an export ban would make matters worse in the long run and would be ineffectual in a free-market economy.

A White House spokesperson declined to say whether the Trump administration is considering a ban, pointing instead to comments by Interior Secretary Doug Burgum, who on Monday said that an export ban on crude oil or fuels would be unlikely to ?help lower retail energy prices.

The White House official also referred to comments made Monday by Jarrod Agen, executive director of the administration's National Energy Dominance Council, who told CNBC the public would soon be hearing about "energy deals" to help bring down energy prices.

Diesel is the economy's workhorse fuel, powering heavy-duty vehicles and machinery. Higher diesel prices probably hit the economy "sooner than gasoline does," said Eric Smith, a professor at Tulane University and associate director of the Tulane Energy Institute.

The U.S. is the world's largest exporter of diesel, with Russia being No. 2.

U.S. distillate inventories, which include diesel, are 13% below their five-year average, according to the latest report from the Energy Information Administration. Gasoline inventories are 5% below their five-year average, the EIA said.

Russia has placed a ban on its own diesel exports through the end of September and is widely expected to extend that moratorium. Ukrainian attacks on Russian energy infrastructure, in response to deadly Russian strikes in Ukraine, have crippled several Russian refineries, putting more pressure on global diesel prices and sending countries that are unable to import Russian diesel scrambling to find the fuel elsewhere. That has made diesel scarcer - and more expensive - globally.

See also: It's not just Hormuz. Another war is providing fresh price shocks to fuel and food.

While a U.S. ban on diesel exports might bring some relief to diesel prices in the short term, its longer-term consequences could potentially be "devastating," said Rebecca Babin, a senior energy trader and managing director at CIBC Private Wealth.

It would be very negative for U.S. refiners and would push global energy prices higher, hitting U.S. prices as well, because the country does not domestically produce all the fuels and crude products it needs, she said.

With an export ban in place, U.S. refiners would likely drop their diesel production significantly, but the U.S. would still need to import certain grades of gasoline and other fuels, Babin said. Those fuel products could become more expensive as refineries outside the U.S. pivot to meet the excess global demand for diesel.

"It's a global market," she said. "[U.S. refiners] would just cut their runs to meet domestic demand," possibly providing some short-term relief.

Ultimately, however, a ban would stress U.S. producers and refiners and ultimately keep the global market "really tight and high," she said.

Victor Reklaitis contributed.

-Claudia Assis