CAMARILLO, Calif. (AP) — The average U.S. price of regular-grade gasoline surged 13 cents a gallon over the past two weeks, to $2.91. And, if plans by the Trump administration to impose sanctions on those countries importing oil from Iran, the price of oil — and gas as a result — will continue to increase.

Industry analyst Trilby Lundberg of the Lundberg Survey said the rising crude oil prices is one of the main reasons for the surge in gas prices.

Lundberg said Sunday prices at the pump have jumped 25 cents over the past month and 60 cents over the past 14 weeks.

The highest average price in the nation is $4.04 a gallon in the San Francisco Bay Area.

The lowest average is $2.45 in Baton Rouge, La.

The average price in Mississippi as of Monday was $2.51 per gallon according to AAA’s gasoline price report, with the average price in Warren County hitting $2.53 per gallon.

According to the weekly GasBuddy survey, Mississippi gas prices have fallen 1 cent per gallon in the past week.

Gas prices in Mississippi are 14.9 cents per gallon higher than a month ago, yet stand 0.6 cents per gallon higher than a year ago.

“The seemingly never-ending streak of rising gasoline prices has largely continued unabated across the country over the last week,” said Patrick DeHaan, head of petroleum analysis for GasBuddy. “Gas prices continue to drift higher, although the pace has slowed somewhat in the last week, but that may end soon as rumors point to an end to U.S. issued waivers that allowed countries to continue buying oil from Iran that may be announced as soon as tomorrow.”

The Trump administration is poised to tell five nations, including allies Japan, South Korea and Turkey, that they will no longer be exempt from U.S. sanctions if they continue to import oil from Iran, officials said Sunday.

Secretary of State Mike Pompeo planned to announce Monday that the administration will not renew sanctions waivers for the five countries when they expire on May 2, three U.S. officials said. The others are China and India.

It was not immediately clear if any of the five would be given additional time to wind down their purchases or if they would be subject to U.S. sanctions on May 3 if they do not immediately halt imports of Iranian oil.

“Such a loss of oil in the current environment of OPEC cuts and rising demand would only serve to cause gas prices to continue advancing, something that has repeatedly drawn the scorn of President Trump, but with such a policy change and waivers perhaps ending, it could directly cause another round of gas price increases just as the national average reaches its highest level in months and points to a more painful summer at the pump,” Dehaan said. “With such a policy move, if OPEC fails to increase output to offset the likely drop from an end to Iran waivers, expect oil prices to continue to surge. This will cost Americans billions if the administration enforces the end to waivers.”

The administration granted eight oil sanctions waivers when it re-imposed sanctions on Iran after Trump pulled the U.S. out of the landmark 2015 nuclear deal. They were granted in part to give those countries more time to find alternate energy sources but also to prevent a shock to global oil markets from the sudden removal of Iranian crude.

U.S. officials now say they do not expect any significant reduction in the supply of oil given production increases by other countries, including the U.S. itself and Saudi Arabia.