President Donald Trump has insisted the blockade on the Strait of Hormuz will “remain in full force and effect” in spite of an announcement by Iran’s foreign minister declaring it “completely open.”

Until modalities for the reopening are completed, Mr Trump on Friday said the U.S. naval blockade will continue in the Gulf region.

“The Strait of Hormuz is completely open and ready for business and full passage, but the naval blockade will remain in full force and effect as it pertains to Iran, only, until such time as our transaction with Iran is 100% complete,” Mr Trump wrote on Truth Social.

The U.S. leader assured that the transaction “should go very quickly in that most of the points are already negotiated.”

At least 19 vessels attempting to cross the strait have been turned back since Washington activated the blockade earlier this week, with no ship successfully passing through the U.S. Navy cordon.

Despite the announcement of the strait’s reopening, energy companies are still wary of dispatching oil tankers through the strait.

Oil prices, which had soared as high as $111 per barrel, fell to $89 on Friday after Iran’s foreign minister Abbas Araghchi declared the strait open.