The US is sending a Patriot air defence missile system and a warship to the Middle East amid escalating tensions with Iran.
The USS Arlington, which transports amphibious vehicles and aircraft, will join the USS Abraham Lincoln strike group.
US B‑52 bombers have also arrived at a base in Qatar.
The US Patriot missile defence system[Photo:BBC]
It said the moves were a response to threats of possible operations against US forces in the region by Iran.
BBC reports the US has given little information about the exact nature of the reported threat, which Iran has dismissed as nonsense, describing the deployments as "psychological warfare" aimed at intimidating the country.
Meanwhile Iran news agency Isna quoted a senior Iranian cleric, Yousef Tabatabai‑Nejad, as saying that the US military fleet could be "destroyed with one missile".