Strait of Hormuz: Map shows where US Navy will blockade Iran

President Donald Trump is following through on a threatened blockade of Iranian ports by U.S. forces after peace talks broke down between the United States and Iran on April 12.

The blockade started close to 10 a.m. ET April 13. It will affect "vessels of all nations entering or departing Iranian ports and coastal areas, including all Iranian ports on the Arabian Gulf and Gulf of Oman," according to the U.S. Central Command.

At least 15 U.S. warships will be part of the blockade, according to an unidentified official cited by The Wall Street Journal. The U.S. military has not officially released specifics of the blockade, nor has it released information about the number of warships involved and whether warplanes will be used. NATO allies are refusing to join the blockade.