The move comes after the U.S. and Iran exchanged fire for the third weekend in a row, raising the specter of a return to all-out war after a shaky ceasefire took effect in June.

The U.S. and Iran have made conflicting statements about whether the Strait of Hormuz is open to shipping traffic.

The move comes after the U.S. and Iran exchanged fire for the third weekend in a row, raising the specter of a return to all-out war after a shaky ceasefire took effect in June.