Oil prices touched their highest level in 4 years. What does it mean for shoppers?

Global oil prices on Thursday touched their highest level in four years as negotiations between the U.S. and Iran showed little sign of resolving a historic energy crisis.

Brent futures, the benchmark index for global oil trading, vaulted as high as $126 a barrel, before dropping to $114 a barrel. Still, that price stands more than 10% higher than it registered five days ago. A separate measure of U.S. oil prices also soared this week, but fell short of multi-year records.

The recent surge in oil prices will likely push up gasoline and other fuel costs over the coming days, some analysts told ABC News. Within weeks, they said, the jump in prices could spread to groceries, furniture and just about any other item delivered by diesel-fueled trucks and tankers.

Shoppers are already smarting  from financial strain, analysts from Edward Jones and EY-Parthenon said. Before this week, oil prices had jumped about 50% since the Iran war broke out on Feb. 28. The energy shock sent overall inflation rising in March.

A sustained rise in oil prices "could exacerbate the pressure on U.S. households," James McCann, a senior economist for investment strategy at Edward Jones, said in a statement to ABC News.

The Middle East conflict prompted the Iranian closure of the Strait of Hormuz, a maritime trading route that facilitates the transport of about one-fifth of global oil supply.

The vast majority of oil that passes through the strait is bound for Asian markets. But since oil prices are set on a global market, prices have climbed for just about everyone as buyers chase fewer barrels of crude.

A U.S.-Iran ceasefire has entered its fourth week, averting a resumption of wide hostilities while leaving the strait under Iran's effective control. The U.S. has mounted a blockade of Iran's ports in the strait, squeezing a key source of Iranian government funds derived from oil exports, but exacerbating the global petroleum shortage.

The average price of a gallon of gas jumped to $4.30 as of Thursday, hitting its highest level since 2022, AAA data showed.

Roughly one of every 10 low-income households is spending more than 10% of its monthly income on gas, Bank of America said in a research report shared with ABC News on Tuesday, citing internal data. For middle- and upper-income households, the share spending that much on gas drops stands at about one of every 20.

The pain at the pump could very well worsen over the coming days, Patrick De Haan, a petroleum analyst at GasBuddy, said in an X post on Wednesday. The average price of a gallon of gas is on track to hit $4.50 by next week, which would amount to a nearly 5% jump, De Haan said.

The rise in oil prices is also expected to push up the cost of diesel fuel, which powers many of the trucks, trains and ships that transport products across a vast global supply chain. The price hike for any individual item will likely be modest, but the pileup of extra costs could weigh on wallets, analysts previously told ABC News.

"Price pressures are expected to intensify through the summer, particularly as higher energy, food and commodities costs feed through," consulting company EY-Parthenon said in a statement on Thursday.

The prospect of higher costs comes as price increases for food, transportation and apparel each clock in above the Federal Reserve's target rate of 2%.

Transportation prices jumped 4.1% over the year ending in March, the most recent month for which data is available, U.S. Bureau of Labor Statistics data showed. Apparel prices climbed 3.4% over that period, while food prices increased 2.7%.

Speaking at a press conference in Washington, D.C., on Wednesday, Fed Chair Jerome Powell warned of far-reaching price increases if oil prices continue to rise.

"We're very well aware that people are experiencing higher gas prices all over the country now -- and that hurts," Powell said, noting that high oil costs would soon show up in "other products and services that are dependent upon petroleum."

"People are going to start to feel that," Powell added.

To be sure, the forecast remains unclear. Oil prices are often highly volatile, even in the absence of a historic shortage.

Oil prices remain below the highs reached after some previous economic shocks. In 2022, the price of Brent crude surged above $139 per barrel in March, just weeks after the Russian invasion of Ukraine. During the 2008 financial crisis, U.S. gasoline prices shot up as high as $147 a barrel.

On Wednesday, Powell called the economic outlook "highly uncertain," summing up the posture of central bank policymakers in 14 words.

"We're kind of waiting to see what happens with events in the Middle East," Powell said.