Washington DC - President Donald Trump on Thursday said he had ordered the US Navy to "shoot and kill" any boats laying mines in the Strait of Hormuz, as US forces seized a tanker reportedly transporting oil from Iran.

"I have ordered the United States Navy to shoot and kill any boat, small boats though they may be... that is putting mines in the waters of the Strait of Hormuz. There is to be no hesitation," Trump said 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!"

After the US and Israel began unprovoked attacks on Iran on February 28, Iran responded by effectively blocking the Strait of Hormuz, threatening to attack any enemy vessels that did not obtain its permission to transit the waterway.

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The blockade caused major disruptions to global trade, sending energy prices soaring and sparking frantic measures to prevent fuel shortages.

The reopening of the Strait of Hormuz has been a major sticking point in negotiations to end the war after a two-week ceasefire began on April 8.

Days later, the US implemented a blockade affecting ships coming from or heading to Iranian ports, although dozens of Iranian ships have reportedly successfully passed through.

Earlier on Thursday, the Pentagon said US forces seized a tanker transporting oil from Iran, after Tehran claimed responsibility for three attacks on three commercial vessels in the key Strait of Hormuz a day earlier.

Trump unilaterally extended the ceasefire on Tuesday, but the blockade remains in place.

The US military boosted its presence in the region on Thursday, with the arrival of a third aircraft carrier.

US Central Command (CENTCOM) said that the USS George H W Bush had arrived in its area of responsibility.

"Nimitz-class aircraft carrier USS George H.W. Bush (CVN 77) sails in the Indian Ocean in the U.S. Central Command area of responsibility, April 23," CENTCOM said in a post on X.