file, some times provocative exercises at sea. a con front taegs with iran, forcibly boarding an iranian ship would be extraordinary. pentagon officials acknowledge moving additional u.s. warships to the region provides additional options to assist the saudi led coalition if necessary. they want to have a naval presence, but also to keep an eye on what the vessels do and itch the vessels are allowed to dock, what is unloaded and where those supplies go. reporter: it is the rapid deterioration on the ground in yemen that the u.s. is most concerned with. recent air strikes in the houthi controlled yemeni capital have killed 25 and wounded 400. all this as the u.s. tries to finalize a nuclear deal with the iranians and urge release of u.s. citizens held in iran. among them the washington post journalist, who is now facing four charges in claweding spying, and aiding a hostile