Obama is rushing to bolster the defense of Iran's Arab neighbors amid fears of the growing possibility of a missile strike by Tehran.
His administration was reported on Sunday to have increased patrols by its warships in the Gulf and to be rapidly escalating the deployment of Patriot anti-missile batteries in Gulf states that fear an attack from Iran.
There is particular concern over the threat to oil installations. Iran has hinted of its capacity to disrupt the passage of tankers in the Gulf, a threat with the potential to disrupt the world oil market.
News of the initiatives, which include an increase in the number of "special" naval patrol vessels off Iran's coast, comes as Washington and its western allies have virtually given up on Obama's efforts to persuade the Iranians to pursue meaningful negotiation over their nuclear programme.