President Donald Trump has said he ordered the United States Navy to “shoot and kill” any Iranian boat laying mines in the Strait of Hormuz, a move that could jeopardise the fragile ceasefire between the two countries.

The US president also said on Thursday that the military will heighten its efforts to remove explosives from the strategic waterway.

“I have ordered the United States Navy to shoot and kill any boat, small boats though they may be (Their naval ships are ALL, 159 of them, at the bottom of the sea!), that is putting mines in the waters of the Strait of Hormuz. There is to be no hesitation,” Trump wrote in a social media post.

“Additionally, our mine ‘sweepers’ are clearing the Strait right now. I am hereby ordering that activity to continue, but at a tripled-up level!”

Iranian officials have repeatedly promised that their country would defend itself and respond to any US attack.

Hormuz – which had been open without interruption before the war – has emerged as a major point of contention in this war.

Iran closed down the strait in response to the US-Israeli military campaign, and it is now suggesting that it has rights to the passage that links the Gulf to the Indian Ocean – parts of which go through Iranian territorial waters.

The closure of Hormuz has spiked oil prices, putting political pressure on Trump at home in the US, where the price of one gallon (3.8 litres) of petrol has surpassed $4, up from $3 before the conflict.

Dueling blockades

About 20 percent of the world’s oil and natural gas flowed through Hormuz before the war.

After a two-week ceasefire came into effect last month, Trump announced a naval siege on Iranian ports and kept it in place even after Tehran announced reopening Hormuz in response to the inclusion of Lebanon in the truce.

Iran has set lifting the blockade as a precondition for resuming talks with the US.

Trump extended the ceasefire that was set to expire on Wednesday, but Washington has kept its blockade on Iran-linked ships.

The Pentagon said on Thursday that the US military conducted a “maritime interdiction and right-of-visit” to a tanker carrying Iranian oil in the Indian Ocean.

Earlier this week, the US military also said it seized an Iranian vessel and ordered dozens of others to turn around.

Meanwhile, Iran has also captured foreign commercial vessels around the Hormuz Strait, which it said were in violation of naval regulations.

The duelling blockades risk re-igniting the war. The US has not set a deadline for the extended truce.

The White House said on Wednesday that Trump is “satisfied” with the siege on Iran.

Trump says Hormuz ‘sealed up tight’

Although Iran has all but halted vessel traffic in the waterway, Trump said on Thursday that the US has “total control over the Strait of Hormuz”, adding that the passage is “sealed up tight”.

The US president also reiterated his claim that the Iranian leadership is divided.

“Iran is having a very hard time figuring out who their leader is! They just don’t know!” Trump wrote on his Truth Social platform.

“The infighting is between the ‘Hardliners’, who have been losing BADLY on the battlefield, and the ‘Moderates’, who are not very moderate at all (but gaining respect!), is CRAZY!”

Earlier in the day, Trump shared a post by conservative commentator Marc Thiessen, calling for the assassination of Iranian officials who oppose diplomacy with the US.

“If there are two factions in Iran, one that wants a deal and one that doesn’t, let’s kill the ones who don’t want a deal,” it said.

Despite Trump’s repeated claims, there has been no evidence of a rift within the leadership in Iran.

Although US and Israeli strikes killed Iranian Supreme Leader Ali Khamenei and several top officials, there have been no major defections within the ruling system.

Last month, Khamenei was replaced by his son Mojtaba, who had been wounded in US attacks, according to the Pentagon.

Mojtaba Khamenei is yet to make a public appearance since he succeeded his slain father, raising speculation about his health.

But Iranian officials, including the lead negotiators – Foreign Minister Abbas Araghchi and Parliament Speaker Mohammad Bagher Ghalibaf – have voiced a unified position in rejecting the US blockade.

Iranian leadership also agreed to the ceasefire and enforced it earlier this month.

On Thursday, Iran’s Foreign Ministry praised the Islamic Revolutionary Guard Corps (IRGC), the ideologically driven military branch spearheading the war effort.

“We salute the noble defenders and guardians of the homeland, and honour the memory of the crimson-shrouded martyrs of the IRGC,” Iranian Foreign Ministry spokesperson Esmaeil Baghaei said in a post on X, marking the anniversary of the establishment of the Revolutionary Guard.