WASHINGTON — Behind closed doors, the White House is urging lawmakers to remain composed as the conflict in Iran enters its 12th day. Officials emphasize the necessity of eliminating threats posed by the Islamic Republic to the United States and its allies.

A senior White House official confided to The Post that the administration is reassuring nervous Republicans that any temporary rise in fuel prices is justified by the promise of future benefits.

Although many Republicans in Congress are outwardly supportive of President Trump’s military actions in Iran, they are privately concerned about the repercussions and the potential impact on upcoming midterm elections. Some are subtly advising the President to conclude the operation swiftly.

“Our military’s performance is nothing short of remarkable,” said Senator Josh Hawley (R-Mo.) during an appearance on Fox News’ “Jesse Watters Primetime” on Tuesday. “It’s been a historic success.”

“Now is the time to declare victory,” he added.

Earlier this week, lawmakers were informed that the initial two days of Operation Epic Fury incurred costs of approximately $5.6 billion. However, as the conflict continues into its 12th day, the overall expenditure remains unclear to Congress members.

“I think probably tens [of billions of dollars], but I don’t know,” House Appropriations Committee Chairman Tom Cole (R-Okla.) told The Post.

“Whether you agree or disagree with Iran, look, we are perilously low on some of the ammunition stocks that we would need if, God forbid, and nobody wants this, we got into a confrontation in the Western Pacific with the Chinese,” he added at another point during a wide-ranging interview.

“This is the time to do that to rebuild the industrial base inside the United States.

During their annual policy retreat in Doral, Florida, House GOP leadership strategized over how to wrangle through a supplemental package to fund the war effort in Iran, a GOP aide told The Post.

One option contemplated was tucking it into a follow-up reconciliation package to the One Big Beautiful Bill Act, the source explained.

House Minority Leader Hakeem Jeffries (D-NY) has kept his powder dry on how Democrats will respond to a formal request for additional military spending. Though he has backed a war powers resolution to stop the fighting.

Perhaps the biggest pain point worrying lawmakers is the impact of the war on oil prices. Iran has launched attacks in the Strait of Hormuz, where about a fifth of the world’s seaborne oil flows through annually.

The effort is seemingly intended to make the war as painful as possible for the US and the world.

“The greatest danger for the Trump administration right now is if they close down the Strait of Hormuz [and] we can’t keep that open,” Sen. Ron Johnson (R-Wis.) told The Post. “That’s not going to be good for oil prices, gasoline prices, affordability.”

“I don’t know what sleeper cells are in here [if] they activate those,” he added. “This was not an easy decision for Trump to make. This was a risky decision for Trump to make. But he had to do it.”

Nationally, gasoline prices are nearing $3.6 per gallon, according to data from the American Automobile Association. They were below $3 a gallon before the war broke out.

Oil prices also blew past $100 a barrel briefly on Monday, but have since dropped back down to around $85.

Trump has contended that gasoline “prices are coming down very substantially.”

“I figured we’d be hit a little bit. We were hit less than I thought and we’ll be back on track in a pretty short while,” he told reporters Wednesday.

The International Energy Agency announced on Wednesday that its members are planning to release 400 million barrels of oil to stabilize markets amid the chaos at the Strait of Hormuz.

But some GOP pols are worried that a protracted conflict in Iran could deal enough of a blow to oil prices to upset voters.

“We are behind the eight ball as far as the electoral process,” Paul, a longtime critic of US interventionism, bluntly assessed to Fox Business Network’s “Mornings with Maria” on Tuesday.

“If you add in high gas prices, high oil prices, and if we are still bombing Iran with kinetic action — people don’t want to call it war — if there’s still kinetic action that causes oil to be over $100, I think you’re going to see a disastrous election,” Paul predicted.

The War Powers Act of 1973 restricts the president from ordering troop engagement abroad for more than 60 days without congressional approval. That law also allows for a 30-day extension.

Trump has been coy about the precise timeline for when the war in Iran will end, after initially suggesting it may carry on for four weeks, before later claiming that the US is ahead of schedule.

“Any time I want it to end, it will end,” he told Axios.