President Donald Trump issued an executive order on Wednesday to sanction Iran's steel, aluminium, copper and iron sectors, which provide crucial foreign currency earnings for its crippled economy. Trump also threatened further action unless Tehran "fundamentally" changed its behaviour."
"A warship, USS Arlington, with amphibious vehicles and aircraft on board, will also join the USS Abraham Lincoln strike group in the Gulf.
And US B-52 bombers have arrived at a base in Qatar, the Pentagon said.
The US said the moves were a response to a possible threat to US forces in the region by Iran, without specifying. Iran dismissed the claim as nonsense."
The Patriot system can counter ballistic missiles, cruise missiles and advanced aircraft.