US officials reportedly said clearing mines in the Strait of Hormuz could take at least six months as Iran warned the vital waterway was 'impossible' to reopen.

The narrow strait – through which one-fifth of the world's oil supply traverses – has become a major hurdle in the US effort to reach a deal with Iran.

President Trump set conditions to end the war that include Iran ending its nuclear program, turning over its highly-enriched uranium, and opening the strait.

Trump had threatened broader military action if Iran did not agree to his demands. However, he announced Tuesday that he would indefinitely extend the ceasefire.

Iran has stalled peace negotiations unless Trump ends a naval blockade he imposed to damage the country's oil-based economy.

Mohammad Bagher Ghalibaf, the speaker of the Iranian parliament and a lead negotiator, argued late Wednesday that reopening the strait would be 'impossible.'

Ghalibaf said the US and Israel are committing 'flagrant' breaches of the ceasefire agreement including the naval blockade, 'the hostage-taking of the world's economy' and 'Zionist warmongering.'

He added in a post on X that the US and Israel 'did not achieve their goals through military aggression, nor will they through bullying.' 

But US officials have now warned about another unexpected hurdle to opening the strait. 

A senior defense department official told members of the House Armed Services Committee on Tuesday that it could take six months to clear the waterway of mines the Iranian military has deployed, according to the Washington Post. 

Any efforts to remove the mines won't even begin until the war ends, the official warned.

The Iranian navy began placing mines in the Strait of Hormuz in March, as US-Israeli forces continued their joint attacks on the country.

The Pentagon then highlighted an effort to attack the Iranian ships that were laying the mines. 

Defense Secretary Pete Hegseth proclaimed that US forces were destroying the ships with 'ruthless precision' as he declared that the US 'will not allow terrorists to hold the Strait of Hormuz hostage.' 

But Iranian forces are now reportedly having trouble finding all of the mines they deployed in the waterway.

The US may now also have trouble finding the mines, some of which were floated remotely using GPS technology - which makes it difficult for American forces to detect the mines when they are deployed, the senior defense official reportedly told lawmakers at the hearing on Tuesday.

Others are believed to have been laid by Iranian forces using small boats.

In total, officials who spoke with the Washington Post said they were told Iran may have placed 20 or more mines in and around the Strait of Hormuz. 

The assessment came after President Trump posted to social media on Friday that 'Iran, with the help of the USA, has removed or is removing, all sea mines.'

It now remains unclear what options the US may use to clear the waterway of the mines, as officials mull whether to use helicopters, drones or explosive ordnance disposal divers. 

As the standstill between the US and Iran now continues, Iran's Islamic Revolutionary Guard Corps said on Wednesday it stopped two ships trying to cross the strait and brought them to shore, according to The Guardian.

Iran's semi-official Tasnim news agency reported that the IRGC accused the two ships - the Panama-flagged MSC Francesca and the Liberia-flagged Epaminondas - of 'attempting to exit the Strait of Hormuz covertly.'

The Epaminondas is Greek-operated, and Greece's foreign minister confirmed on Wednesday that there had been an attack on a Greek-owned cargo ship.

A UK-based maritime security monitor also reported attacks on the ships on Wednesday, claiming that a vessel was approached by an Iranian gunboat 'that then fired upon the vessel, which has caused heavy damage to the bridge.'

The seizure on Wednesday marks the first time since the war began that Iran has taken control of ships in the waterway. 

The change in its strategy comes after US forces fired on and seized an Iranian cargo vessel and boarded an Iranian oil tanker in the Indian Ocean over the weekend.

Despite the apparent escalation on Wednesday, White House Press Secretary Karoline Leavitt insisted that President Trump was 'satisfied' with the US naval blockade and 'understands Iran is in a very weak position.'

'The cards are in President Trump's hands right now,' she said, arguing that the US was 'completely strangling their economy through this blockade - they're losing $500 million a day.' 

Yet a prolonged closure of the Strait of Hormuz can have dire effects on the oil and gas markets as insurers, ship owners and captains will continue to have reservations about moving through the mine-infested waterway.

'You're not going to have many people wanting to run that risk,' Richard Nephew, an expert on Iranian diplomacy and a senior researcher at Columbia University, told the Washington Post.

Gas prices in the US have already soared since the war with Iran began in late February, with the average cost of a gallon of gas rising to $4.02 on Wednesday, according to AAA.

That is up from $2.98 just before the war began.

Treasury Secretary Scott Bessent has also warned it could be late September before 'we can have $3 gas again.'

But if the sky-high gas prices persist, Republicans fear they may lose the midterm elections in November.

Defense spokesman Sean Parnell, though, seemed to deny the timeframe in a brief statement to the Washington Post, calling the information it published 'inaccurate.'

The Daily Mail has also reached out to the Department of Defense for comment.