US Central Command vowed to begin a blockade of "all maritime traffic entering and exiting Iranian ports".
"US Central Command (CENTCOM) forces will begin implementing a blockade of all maritime traffic entering and exiting Iranian ports on April 13 at 10 a.m. ET [14:00 GMT], in accordance with the President’s proclamation," the command said in a statement.
The command asserts that the blockade will be applied "impartially against vessels of all nations entering or departing Iranian ports and coastal areas, including all Iranian ports on the Arabian Gulf and Gulf of Oman."
"CENTCOM forces will not impede freedom of navigation for vessels transiting the Strait of Hormuz to and from non-Iranian ports," it added.