Tehran had previously conveyed to Washington that it would respond firmly if the U.S. directly attacked Iran, and it has warned that U.S. assets in the region could be a target if it was attacked.
The U.S., which has long had major military bases in the Gulf Arab States, moved some aircraft and ships last week that may be vulnerable to a potential Iranian attack and limited access to its largest installation, Al Udeid Air Base in Qatar.
Below is a map of U.S. facilities in the region.
