President Trump threatened to destroy Iranian ships in the Strait of Hormuz on Monday, just minutes before a US blockade was set to begin in the region.

“Iran’s Navy is laying at the bottom of the sea, completely obliterated – 158 ships,” wrote Trump on Monday morning.

He noted the US has not targeted a small number of what they call “fast attack ships”, because “we did not consider them much of a threat.”

“Warning: If any of these ships come anywhere close to our BLOCKADE, they will be immediately ELIMINATED, using the same system of kill that we use against the drug dealers on boats at Sea,” he added.

Over the weekend, Trump announced that the US would begin a blockade in the Strait of Hormuz on Monday at 10 a.m. ET, restricting vessels entering and leaving the critical waterway.

The move is intended to cut off Iran’s ability to export oil and reduce the country’s control over the passage.

Oil futures trimmed earlier gains but still remained above $100 per barrel on Monday.