The United States military is “not ready” to accompany oil ships through the Strait of Hormuz, a top official in President Donald Trump’s administration says as Iran continues to block the strategic waterway.

US Energy Secretary Chris Wright told the CNBC business news channel on Thursday that the markets are experiencing a “short-term disruption”, predicting that the war would go on for “weeks, not months”.

Despite Trump’s repeated threats, Iran has largely succeeded in shutting down the strait, which links the Gulf to the Indian Ocean. The closure has sent oil prices soaring.

Wright described the effects of the crisis as “short-term pain for long-term gain”, arguing that the US is “destroying” Iran’s ability to threaten the energy market.

Last week, Trump suggested that the US Navy would escort ships through the Gulf, but Wright said on Thursday that the move “can’t happen now”.

“We’re simply not ready. All of our military assets right now are focused on destroying Iran’s offensive capabilities and the manufacturing industry that supplies their offensive capabilities,” the energy secretary said.

“We don’t want this to be a brush-off for a year or two. We want to permanently destroy their ability to build missiles, to build roads, to have a nuclear programme.”

His comments came as Iran’s new supreme leader, Mojtaba Khamenei, affirmed in his first public comment since being selected to succeed his assassinated father, Ali Khamenei, that the Strait of Hormuz should remain closed during the war.

“The will of the people is to continue effective and deterrent defence,” Khamenei said in a written statement. “The tactic of closing the Strait of Hormuz must also continue to be used.”

The Iranian military has said it would “welcome” the US Navy escorting oil ships, suggesting it is prepared to strike US forces in the narrow waterway.

On Wednesday, three commercial vessels were attacked near the strait.

Wright announced earlier this week on social media that the US Navy had escorted an oil ship through the strait, then quickly deleted the post. The White House subsequently confirmed that the claim was not true.

It is not clear why the statement was released and then retracted.

Assurances by US officials that Washington would open the strait have temporarily calmed markets, only for prices to spike again.

The price of a barrel of oil peaked at about $120 on Sunday, up from about $70 before the US and Israel launched the war on February 28. It has been yo-yoing between $80 and $100 for the past few days.

In addition to the marine blockade, Iran has targeted oil installations across the Gulf.

As one of the world’s largest oil producers, the US is largely self-sufficient. But possible shortages in Asia and Europe have put a strain on prices globally.

According to data from the American Automobile Association, the average price of one gallon (3.78 litres) of petrol in the US is now $3.60, up from $2.94 last month.

Rising energy prices could fuel inflation and affect the cost of basic goods, including food.

But Trump suggested on Thursday that the US is benefitting from skyrocketing oil prices.

“The United States is the largest Oil Producer in the World, by far, so when oil prices go up, we make a lot of money,” the US president wrote in a social media post.

“BUT, of far greater interest and importance to me, as President, is stopping an evil Empire, Iran, from having Nuclear Weapons, and destroying the Middle East and, indeed, the World.”

Iran denies seeking a nuclear weapon, and Trump reiterated for months before the current conflict that US strikes against Iranian facilities in June had “obliterated” the country’s nuclear programme.