Washington DC - President Donald Trump warned Iran Tuesday of unprecedented military consequences if it mines the Strait of Hormuz, after Tehran vowed that no Gulf oil would pass through the key waterway.

Trump said on social media that he had received no reports of Iran doing so yet, but then said that if Tehran had, then it must remove the floating explosive devices "IMMEDIATELY!"

"If for any reason mines were placed, and they are not removed forthwith, the Military consequences to Iran will be at a level never seen before," Trump said on his Truth Social network.

"If, on the other hand, they remove what may have been placed, it will be a giant step in the right direction!"

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The US would also use the missiles it had previously employed to blow up vessels in Latin American waters to "permanently eliminate" any mine-laying boat in the Gulf strait, Trump added.

"They will be dealt with quickly and violently. BEWARE!" he posted.

His post came after CNN – citing anonymous sources familiar with US intelligence reports – reported that Iran had indeed begun laying mines in the Strait of Hormuz, through which nearly a fifth of global oil production passes, and where traffic has virtually halted.

The White House said earlier Tuesday that US has not escorted any oil tanker through the Strait of Hormuz, after the energy secretary's social media account posted but then deleted a claim that it did so.